^ARThS SOEWCES USHAH1

A Revision of the Parainfraclass Archosauria Cope, 1869, Excluding the Advanced Crocodylia

George Olshevsky

Mesozoic Meanderings #2

Published by: George Olshevsky Publications Requiring Research Post Office Box 16924 San Diego, California 92176-6924

Price: $20.00

First printing (October 24, 19i>l): 100 copies, of which this is # /C /

Signed by author: j>r £Vr

Contents

PREFACE 1 Parasuborder: Erythrosuchia Bonaparte, Acknowledgments 3 1982 40 Technical Review 4 Parafamily: INTRODUCTION 5 Watson, 1917 40 Materials and Methods 6 Parasuborder How To Use This List: Conventions 7 Bonaparte, 1982 41 TAXONOMIC CONSIDERATIONS 13 Family: The Problems of Cladistic von Huene, 1942 41 Classifications 14 Rauisuchia 42 Linnaean Taxa at the Ordinal Level .. .19 Suborder Poposauria nov. 43 New Subfamilial Taxa 21 Family: Teratosauridae Cope, 1871 ... 43 PHYLOGENY 25 incertae sedis 44 Defining 26 Family: Ctenosauriscidae Early Archosaurs 28 Kuhn, 1964 44 Thecodontian Orders 29 Family: Teleocrateridae Romer, 1966 .. 44 Superorder: THECODONTU Owen, 1859 . 31 : PARASUCHIA Huxley, 1875 44 Paraorder: Family: Parasuchidae Lydekker, 1885 .44 Broom, 1906 37 Order: AETOSAURIA Family: Mesenosauridae Nicholson & Lydekker, 1889 49 Romer, 1956 37 Family: Stagonolepididae Family: Proterosuchidae Lydekker, July 1887 49 von Huene, 1914 37 Aetosauria incertae sedis 50 Proterosuchia incertae sedis 38 Order: CROCODYLIA Gmelin, 1788 .... 50 Order: ORNITHOSUCHIA Suborder Trialestia Crush, 1984 51 Bonaparte, 1971 38 Family: Trialestidae Bonaparte, 1982 .. 51 Parafamily: Euparkeriidae Suborder: Sphenosuchia von Huene, 1920 38 Bonaparte, 1971 51 Family: Erpetosuchidae Family: Pedeticosauridae Watson, 1917 38 van Hoepen, 1915 51 Family: Family: Hemiprotosuchidae von Huene, 1908 38 Crush, 1984 51 Order: PSEUDOSUCHIA Family: Sphenosuchidae Zittel, 1887-90 39 von Huene, 1922 51 Suborder: Arcfaaeosuchia SilL 1967 39 Family: Lewisuchidae nov. 51 Family: Parasuborder: Mook, 1934 .52 Sill, 1967 39 Family: Brown, 1933 ... 52 Family: Rhadinosuchidae Family: Platyognathidae Hoffstetter, 1955 39 Simmons, 1965 52 Family: Weems, 1980 40

Parainfraclass Archosauria Cope, 1869 Contents Family: Edentosuchidae Marsh, 1876 68 Young, 1973 52 Family: Azhdarchidae Padian, 1986 .. .69 Family: Gobiosuchidae Pterodactyloidia incertae sedis 70 Osm61ska, 1972 53 PHYLOGENY 71 Suborder Hallopoda Marsh, 1881 .53 Defining 71 Family: Hallopodidae Marsh, 1881 ... .53 Origin of the Erect Stance 72 Order HUPEHSUCHIA Early Dinosaurs 74 Young & Dong, 1972 53 The Origins of Avian Flight 76 Family: Nanchangosauridae Comments on Dinosaur Diversity and Wang, 1959 53 85 incertae sedis .53 DINOSAUR ORDERS 89 PHYLOGENY 55 Sauropodomorph Orders 95 Pterosaur Flight -56 Ornithischian Orders 97 Pterosaur Orders 57 Parasuperorder: THEROPODOMORPHA Superorden PTEROSAURU Kaup, 1834 ... ^9 nov 103 Order SHAROVIPTERYGIA nov 59 Paraorder: Basitheropoda nov 103 Family: Scieromochlidae Family: Megalancosauridae nov 103 von Huene, 1914 59 Order: LAGOSUCHIA Paul, 1988 103 Paraorder: RHAMPHORHYNCHOIDIA Family: Lagosuchidae Plieninger, 1901 59 Bonaparte, 1975 103 Family: Eudimorphodontidae Family: Lagerpetonidae Wellnhofer, 1978 59 Arcucci, 1987 103 Family: Dimorphodontidae Order HERRERASAURIA Seeley, 1870 59 Gallon, 1985 104 Family: Anurognathidae Family: Staurikosauridae Nopcsa, 1928 60 Galton, 1977 104 Family: Family: Seeley, 1870 60 Benedetto, 1973 104 Rhamphorfaynchoidia incertae sedis 62 Herrerasauria incertae sedis 104 Order PTERODACTYLOIDIA Paraorder: Marsh, 1881. .105 Plieninger, 1901 62 Parasuborder Family: Pterodactylidae Marsh, 1884 105 Bonaparte, 1838 62 Family: Podokesauridae Family: Germanodactylidae von Huene, 1914 105 Young, 1964 63 Family: Halticosauridae Family: Ctenochasmatidae von Huene, 1956 106 Nopcsa, 1928 64 Family: Family: Pterodaustridae Marsh, 1884 emend. Gilmore, 1920 .106 (Bonaparte, 1971) 64 Family: Family: Dsungaripteridae Huxley, 1869 107 Young, 1964 64 Family: Family: Bonaparte & Novas, 1985 109 (Seeley, 1870) 65 Family: Family: Criorhynchidae Bonaparte & J. Powell, 1980 110 Hooley, 1914 67 Ceratosauria incertae sedis 110 Family: Suborder: Spinosauria nov. 110 Campos & Kellner, 1985 67 Family: Baryonychidae Family: Tapejaridae Kellner, 1989 67 Charig & Milner, 1986 110 Family: Nyctosauridae Bennett, 1989 . .68 Family. Stromer, 1915 .110 Family:

Contents ii Meanderings #2 Suborder: Order: BRONTOSAURIA nov 129 von Huene, 1920 HI Parasuborden Prosauropoda Parafamily Eustreptospondylidae von Huene, 1920 129 Paul, 1988 HI Family Thecodontosauridae Lydekker, Family: Marsh, 1878 111 1890 129 Family: Itemiridae Kurzanov, 1976 .. .113 Family Anchisauridae Marsh, 1885 .. 129 Family. Dryptosauridae Marsh, 1890 .114 Family Parafamily: Aublysodontidae von Huene, 1914 130 Nopcsa, 1928 114 Family Yunnanosauridae Family: Young, 1942 130 Osborn, 1905 115 Family Marsh, 1895 .. 131 Carnosauria incertae sedis 117 Family Parasuborden Protoavifonnes von Huene, 1929 133 Chatterjee, 1991 119 Family Blikanasauridae Family: Protoavidae Chatterjee, 1991 . .119 Gallon & van Heerden, 1985 133 Suborder Suborder: Marsh, 1878 135 von Huene, 1914 119 Family Barapasauridae L. B. Halstead Family. & J. Halstead, 1981 135 Cope, 1875 119 Parafamily Family Marsh, 1881 119 Lydekker, 1888 136 Family Family Brett-Surman & Paul, 1985 121 Riggs, 1904 137 Suborder Family Cope, 1877 .140 Barsbold, 1976 121 Family Euheiopodidae Kuhn, 1965... 141 Family Family Marsh, 1884 ... 142 Marsh, 1890 121 Family Family Deinocheiridae von Huene, 1956 143 Osm61ska & Roniewkz, 1970 122 Family Titanosauridae Suborder Lydekker, 1885 144 Colbert & D. A. Russell, 1969 123 Family Chubutisauridae Parafamily del Corro, 1974 146 Huxley, 1871 123 Sauropoda incertae sedis 146 Family Order: SEGNOSAURIA D. A. Russell, 1969 123 Barsbold & Perle, 1980 147 Family Gilmore, 1924 . .125 Family Segnosauridae Perle, 1979 ... 147 Suborder. Family Barsbold, 1976 125 Maleev, 1954 147 Family Segnosauria incertae sedis 147 R. M. Sternberg, 1940 125 Superorder Family Elmisauridae Seeley, 1888 149 Osm61ska, 1981 126 Paraorder: LESOTHOSAURIA nov 149 Family Family Lesothosauridae Barsbold, 1976 126 L. B. Halstead & J. Halstead, 1981 .149 Family Ingeniidae Barsbold, 1986 126 Lesothosauria incertae sedis 149 Suborder: Avimimiformes Paraorder Chatterjee, 1991 126 Osborn, 1923 150 Family Avimimidae Kurzanov, 1981 . .126 Parafamily Scelidosauridae Theropoda incertae sedis 127 Cope, 1869 150 Superorder Family: Marsh, 1890 .. 150 von Huene, 1932 129 Family: Ankylosauridae Brown, 1908 .153

Parainfraclass Archosauria Cope, 1869 Contents Order: Marsh, 1877 ... .155 Family: Marsh, 1888 ... 161 Parafamily. Huayangosauridae Parasubfamily: Eucentrosaurinae Galton, 1990 155 nov 161 Family: Marsh, 1877 .. .155 Subfamily: Paraorden Lambe, 1915 163 Maryanska & Osmdlska, 1974 157 Ceratopsidae incertae sedis 164 Parafamily: Pisanosauridae Order Marsh, 1871... 165 Casamiquela,1967 157 Parafamily: Hypsilophodontidae Parafamily: Dollo,1882 165 Kuhn, 1966 157 Family: Parafamily: Chaoyoungosauridae Milner & Norman, 1984 167 nov. [nomen nudum] 158 Family. Camptosauridae Parafamily: Homalocephalidae Marsh, 1885 167 (Dong, 1978) 159 Parafamily: Family: Pachycephalosauridae Cope, 1869 168 C. M. Sternberg, 1945 159 Family: Hadrosauridae Cope, 1869 ... 170 Order: Marsh, 1890 160 Family. Lambeosauridae Parafamily: Psittacosauridae von Huene, 1948 174 Osbora, 1923 160 Omithischia incertae sedis 177 Parafamily: Protoceratopsidae EXCLUDED TAXA 179 Granger & Gregory, 1923 161 REFERENCES 183

Contents iv Mesozoic Meanderings #2 Preface

HERE WAS A TIME in the early 1970s and Peter Dodson of the University of Pennsyl­ Twhen accumulating dinosaur names was vania sponsored my membership in the Society one of my hobbies. In this I was assisted by the of . (I may eventually University of Toronto Computer Centre, which follow one of Ralph Molnar's original sugges­ because I worked there as a staff programmer tions and add the remaining crocodilians and and graduate student gave me free access to the Mesozoic to my table, but for now the their IBM System/360 computer. This I used to other archosaurs are handful enough.) maintain and occasionally print various lists of In the late 1970s, a freelance publishing ven­ things I was interested in; it was a convenient ture (stemming from another of my computer medium for editing my databases and produc­ lists) I had. initiated paid off. This prompted ing typographically clean output. me to terminate my computer-science doctoral When, in the mid-1970s, Samuel P. Welles, candidacy at Toronto, to abandon program­ then at the University of California at Berkeley, ming computers as a career, and to become a delivered a public dinosaur lecture at the Royal full-time editor of my own publications. As one Ontario Museum, I handed him a copy of the of my projects, in 1978 I produced Mesozoic dinosaur list for his files. In time this fell into Meanderings #1, a published version of the ar- the hands of Michael K. Brett-Surman and chosaur list, which for a few I peddled at Robert A. Long, then both at Berkeley as well. SVP annual meetings. (It sold out long ago.) A letter from Long in 1976 pointed out taxa I After moving to San Diego in 1979,1 produced had overlooked and, to my delight, requested several more paleontological publications, in­ references to taxa unknown to him. In 1977, cluding supplements to Mesozoic Meanderings Ralph E. Molnar requested a printout, and #1. Unfortunately for these projects, by 1981 I soon a multipage letter arrived from him with was locked into publishing a line of indexes to additions, corrections, and suggestions. At the Marvel Comics, for which there was a tremen­ same time, my meanderings through the Royal dously more lucrative market, and I had nei­ Ontario Museum library brought me in touch ther access to a computer nor time to continue with paleontology graduate student David B. paleontological publishing. All I could do was Weishampel, and we would meet from time to maintain my archosaur list manually, visit the li­ time thereafter to exchange information about brary sporadically, and reply to correspon­ new papers and discoveries. I also initiated cor­ dence occasionally. By 1986, the Marvel Index respondences with other paleontologists, who project was consuming 60 or more hours per proved wonderfully generous with their knowl­ week, month after month. edge. Fortunately, I was able to get away every so Naturally, all this input sharply increased the often. I presented two talks (about uniform po- quality of my list, kept me aware of impending lyhedra and about regular four-dimensional po- publications, and greatly augmented my litera­ lytopes: some of the computer work I had done ture collection with original offprints. I also as a graduate student) at a mathematics confer­ added the remaining non-crocodilian archo- ence called "Shaping Space" at Smith College saurs to the dinosaur list. By 1978, Weishampel in 1984. In 1986,1 attended the Dinosaur Syste-

Parainfraclass Archosauria Cope, 1869 1 Preface matics Symposium at the Tyrrell Museum in Al­ load crept upward again, eventually throwing berta, —a symposium I would not have the newsletter off its monthly schedule; Mesozo­ missed for the world. It had occurred to me a ic Meanderings #2 remained on a distant back few months earlier, while I was manually updat­ burner. ing the archosaur list, that elevating the diverse At long last, in the summer of 1991, a block archosaurian suborders to orders would bring of time opened up between editing projects, archosaur systematics more into line with that and I was actually able to prepare a version of of extant and birds. Mammals and the archosaur list for publication. Furthermore, birds are each conservatively classified into a large audience, to whom I can market copies more than 20 orders—more than 30 if the and perhaps recoup some of my production known extinct orders are counted—reflecting and research costs, will be on hand in my home their worldwide distribution and body-plan di­ city at the 1991 SVP annual meeting. In trying versity. Archosaurs, particularly dinosaurs, pter­ to keep my costs low, I have saved layout time osaurs, and birds, filled the terrestrial world and space by eliminating illustrations and leng­ during the Mesozoic Era just as mammals and thy diagnoses of the taxa. Such material would birds do today, so I wondered why there were in any case have been derived largely from only five archosaur orders instead of 30. Are works already published and is abundantly we really ignorant of five-sixths of all the ar­ available in the references listed at the end of chosaurs that ever lived? Have some of the or­ these introductory sections. ders been masquerading as suborders? As I What I have found particularly daunting in hope to show elsewhere in this paper, I think reading and trying to absorb cladistic analyses the answer to both questions is yes. is the enormous number of what seem to be mi­ I presented my conclusions in abstract form croscopically detailed anatomical features list­ at the Tyrrell conference. Rather to my sur­ ed as phylogenetically important characters. I prise, the presentation was received with inter­ suppose this kind of work is necessary, but on est and engendered a post-conference discus­ closer scrutiny, many of the characters seem sion group on dinosaur . It was my less than robust. For example (I pick a few hope to expand the abstract into a paper for from a fine-print figure caption in Evans, the Symposium volume (recently published as 1988): "first and fifth metacarpals shorter than Dinosaur Systematics: Approaches and Perspec­ second and fourth metacarpals; posterior pro­ tives by Cambridge University Press; Carpenter cess of dentary extends beyond coronoid; three & Currie, eds., 1990). The Marvel Index proj­ or less (sic) premaxillary teeth on each side; re­ ect, however, proved too taxing to allow me to duction in length of metatarsals; teeth mediolat- complete the paper before the deadline. I re­ erally expanded; paroccipital process distally solved that if ever time permitted, I would pub­ expanded." What I would like to know when I lish the work myself as Mesozoic Meanderings see such material is just how much of the #2. relevant body part's extension, reduction, or ex­ The Marvel Index project endured until ear­ pansion actually counts. For example, does ly 1988, when I finally gave it up and returned "shorter" mean merely subequal, or does it to freelance editing and publishing. Luckily, it mean strongly reduced? And relative to what is had paid well enough that I was able to pur­ the "reduction in length of metatarsals" to be chase an excellent desktop publishing system, considered: the state in earlier or related taxa, and I soon transferred my hand-compiled ar­ or a different part of the 's ? All chosaur list back into machine-readable form. teeth, being three-dimensional objects, exhibit To augment my freelance income, I initiated a mediolateral expansion; how much is required paleontological newsletter called Archosaurian for this to be considered a character state? Articulations, which in turn inspired Dinama- Rather than reducing the subjectivity present tion International Corporation to hire me for a in the classification process, cladistic analysis while to edit a dinosaur magazine (it has not, seems merely to have subdivided it into a multi­ as of this writing, been published). My work­ tude of subjective microdecisions. And in this

Preface 2 Mesozoic Meanderings #2 context I would also like to understand what it of space, time, and cost to being merely a would mean to the living animal in terms of its sketch. Many of the topics discussed in the in­ adaptability and lifestyle to have, for example, troductory sections require elaboration; some I a distally expanded paroccipital process or a intend to expand myself when I revive my other posterior dentary process extending beyond the paleontological publication, Mesozoic Verte­ coronoid. These comments may seem superfi­ brate Life, perhaps in time for the 1992 SVP an­ cial, but I do not think I am alone in my lament nual meeting. (see, e.g., Charig, 1982; Chang & Milner, 1990). In constructing an archosaur phytogeny and taxonomy that make sense to me—to be de­ ACKNOWLEDGMENTS scribed on the following pages—I have strived to understand a few well-defined archosaurian My archosaur project owes a great deal to anatomical characters from functional and phy- several paleontologists whose boundless enthu­ letic standpoints. Perhaps not surprisingly, I siasm, interest, and eagerness to exchange infor­ haven't been very successful in this. For exam­ mation have often surpassed my own. I can ple, I have neither found in the literature nor only hope that they keep the information com­ been able to contrive a compelling explanation ing, for without it, the archosaur table would for the appearance of the antorbital fenestra, suffer greatly. My unabashed thanks to: Mi­ the key archosaurian synapomorphy. It un­ chael K. Brett-Surman, Eric Buffetaut, Ken­ doubtedly lightened the in , neth Carpenter, Dan Chure, Philip J. Currie, theropods, and primitive birds, but this could Donald Glut, John S. Mcintosh, Ralph E. Mol- not have been the reason it evolved in the nar, Dale A. Russell, and David B. Weishampel. small, lightweight that was the first ar­ Tracy Ford has been of inestimable help in chosaur. And if it was so useful as to persist in keeping me well supplied with photocopies of several major lineages, why did it close secon­ references and in being a sounding-board for darily in such divergent groups as crocodilians some of the taxonomy expressed herein. Tracy and ornithischians? And what was the function has become very good at hunting down obscure of the obturator process on the ornithischian is­ material, and I recommend his services to all in­ chium? Half the known ornithischians got terested parties. along without one, but it is a synapomorphy The archosaur table has also benefited great­ that helps to define one major lineage, the or- ly from conversations and/or correspondence nithopods, that persisted from at least the Mid­ with the following people, who have on various dle through the Late . I can­ occasions over the years provided me with addi­ not imagine that these and other long-lasting tions, corrections, taxonomic suggestions, pho­ characters arose solely for the convenience of tographs of specimens, references, and copies taxonomists. of hard-to-obtain papers: Andrea Arcucci, Har- Throughout the two decades that I have ley Armstrong, Donald Baird, Robert T. Bak- been purposefully collecting information about ker, Christopher Bennett, Michael J. Benton, archosaurs, I have been motivated almost en­ Jos6 F. Bonaparte, Wilham T. Blows, George tirely by curiosity. In a nutshell, I've sought an­ Callison, Kenneth Campbell, Chao Shichin, swers to two very basic questions about them: Alan J. Charig, , Luis M. "What is an archosaur?" and "What are the ar­ Chiappe, Edwin H. Colbert, Walter P. chosaurs?" Every so often I come to a point Coombs, Jr., Ruth A. Cooper of the ICZN Sec­ where I seem to have something worthwhile to retariat, Kyle Davies, Thomas D6mere, Robert say, and I prepare a document like this for any­ K. Denton, Peter Dodson, , one who is interested. The material herein is by James O. Farlow, Peter M. Galton, David D. no means the "final word" on anything, as if Gillette, He Xinlu, Rene Hernandez, John R. something like that were even possible in a Horner, Nicholas Hotton III, Adrian P. Hunt, field so rich with unknowns as paleontology. Stephen Hutt, Louis Jacobs, Sohan L. Jain, Rather, it is presently limited by considerations James A. Jensen, Alexander W. A. Kellner,

Parainfraclass Archosauria Cope, 1869 3 Preface Haang Mook Kim, James Kirkland, Sergei M. McVey, Mary Odano, David Peters, Helen R. Kurzanov, Guy Leahy, Giuseppe Leonardi, Sattler, Peter Von Sholly, William Stout, and Martin G. Lockley, Jean Le Loeuff, Robert A. John B. Wexo. Long, Spencer G. Lucas, James H. Madsen, Finally, my gratitude to my wife, Andrea Ol- Jr., Robert Makela, Larry D. Martin, Ruben shevsky, for her support of all my publishing Martinez, Teresa Maryanska, Niall J. Mateer, schemes, knows no bounds. Dale Mclnnes, Wade Miller, William Morris, This project is supported entirely by sub­ David B. Norman, Fernando Novas, Paul E. Ol- scriptions to Archosaurian Articulations, sales sen, Haiszka Osm61ska, John H. Ostronv^efe of Mesozoic Meanderings and other paleonto- in Padian, Michael Parrish, Gregory S. Paul, logical publications, and whatever freelance Michael Raath, Nicholas Rautian, Thomas editing and writing work I can turn up. If you Rich, J. Keith Rigby, Jr., Timothy Rowe, Ash- like what you see, let your colleagues and insti­ ok SahnL Scott Sampson, Albert P. Santa tution libraries know my mailing address, and Luca, Jos6 Luis Sanz, Andrej G. Sennikov, I'll take it from there. Subscribers to Archosau­ Paul C. Sereno, Bryan SmalL Ken Stadtman, rian Articulations (except libraries and other in­ Hans-Dieter Sues, Philippe Taquet, Darren stitutions) receive an automatic 20% discount Tanke, Leonid P. Tatarinov, Tony Thulborn, off the cover price of any of my publications. Jacques Van Heerden, Samuel P. Welles, Peter Bookstores and other vendors should send in­ Wellnhofer, Rupert Wild, and P. Yadagiri. Any quiries about wholesale discounts to my mail­ misinterpretations of their ideas, suggestions, ing address. or writings in this compilation are entirely my Mesozoic Meanderings is published in print­ own fault. My apologies to anyone Fve omit­ ings of 100 copies. Once a printing sells out, ted; remind me of who you are, and I'll be sure the issue is returned to press—with accumulat­ to include you in the next printing. Once you're ed additions and corrections—tor another 100- on this list, you're on it for life! copy press run. Only the first printing is signed Many thanks also to Carl Masthay, who aid­ and numbered; subsequent printings are just ed me on a number of occasions by translating numbered. The introductory text does not passages from Chinese and Korean papers. change as much between printings as do the I thank Stephen Pickering, who is working table and the census counts. This seems to be on a huge dinosaur compendium of his own, the most cost-effective way of keeping Mesozo­ for sharing some of the results of his research. ic Meanderings perpetually in print and up to Thanks also to Masahiro Tanimoto, who date, and I will continue this system until Meso­ over the years has provided me with numerous zoic Meanderings #3 is ready for publication. Chinese and Japanese references, many of which include beautiful, full-color photographs of specimens simply unavailable anywhere else. TECHNICAL REVIEW A special thanks to the organizers of the Drumheller Dinosaur Systematics Symposium Mesozoic Meanderings is a peer-reviewed "mini-conference": Michael K. Brett-Surman, publication This issue's reviewers include: Mi­ Donald Brinkman, Kenneth Carpenter, Ralph chael K. Brett-Surman (Smithsonian Institu­ E. Chapman, Alan J. Charig, Peter Dodson, tion), Kenneth Carpenter (Denver Museum of Anthony Fiorillo, Tracy Ford, Richard Laub, Natural History), Daniel Chure (Dinosaur Na­ and David B. Weishampel. tional Monument), Philip J. Currie (Tyrrell Thanks also to my "dino pals" for their con­ Museum of Paleontology), Ralph E. Molnar tinued interest in and support of my publica­ (Queensland Museum, ), John S. Mc­ tions: Ben Creisler, Stephen and Sylvia Czer- intosh (Wesleyan University), Dale A. Russell kas, Mark Hallett, Raymond Ham, Doug Hen­ (Canadian Museum of Nature), and David B. derson, David Lambert, Donald Lessem, Joel Weishampel (Johns Hopkins University).

Preface 4 Mesozoic Meanderings #2 Introduction

HIS PUBLICATION has several goals. through the . Recently, argu­ TForemost of these is to present a complete ments have been put forward that the class and current checklist of archosaurian genera Aves (extant from at least the Late and , classified systematically, for the [Chatterjee, 1991] to the present) arose witliin convenience and use of the vertebrate paleonto- the theropod of the (e.g., Os- logical community. With the exception of a now trom, 1976, and others), so cladistic taxono- seriously outdated list that I produced in 1978 mists, such as Gauthier (1986a, 1986b, 1989), (Mesozoic Meandering? #1 and its supple­ Benton & Clark (1988), and Benton (1990a) ments: Olshevsky, 1978, 1979, 1980a, and maintain that Aves should be included in Ar- 1980b), such tables presendy exist only within chosauria as a saurischian subgroup. the contexts of broader paleontological works, These and other systematic studies of the ar­ such as bibliographies {e.g., Chure & Mcintosh, chosaurs absolutely mandate a revision of the 1989), monographic texts (e.g., Carroll, 1988), traditional archosaur classification. For reasons and multiauthored studies (e.g., Weishampel, stated in die next section (Taxonomic Consider­ Dodson & Osm61ska, eds., 1990). As such, they ations), however, I do not think the vertebrate are not always conveniently organized, and it is paleontological community will accept and use not long before they become out of date. By a wholly cladistic reclassification, the only alter­ keeping my print runs small and by maintaining native that such studies have so far offered. I it in machine-readable form as a desktop-pub­ believe the scheme presented here merges Lin- lished document, I can produce an updated naean and cladistic philosophies in a "Stmpson- checklist with each new printing. ian" way that reflects our present knowledge of Another goal of this publication is to pre­ archosaur phylogeny without sacrificing the use­ sent, as a framework for the checklist of genera fulness of the hierarchic Linnaean structure. (I and species, a more streamlined organization will know soon enough whether it satisfies tradi­ for the higher archosaurian taxa. Traditionally, tionalists, cladists, or neither!) the archosaurs have been partitioned into five Taxonomy cannot be done without a solid orders: (1) the Thecodontia, a thoroughly para- phylogeny, and phylogeny cannot be done with­ phyletic assemblage of archosaurs extant al­ out a functional understanding of the charac­ most exclusively during the Triassic Period; (2) ters employed to track and unravel phylogeny the Crocodylia, a well-diagnosed monophyletic from the record. In particular, the phylo- order that has persisted from the Triassic to genetic relationship between theropod dino­ the present; (3) the Pterosauria, another well- saurs and birds, which has been debated at diagnosed monophyletic order, extant from at length in the literature (cf. Hecht, Ostrom, least the through the Late Creta­ Viohl & Wellnhofer, eds., 1985), needs to be ceous; (4) the Saurischia, an order I consider clarified before a reasonably correct taxonomy diphyletic, extant from at least the Late Trias­ for those two groups can be established. Thus sic through the Late Cretaceous; and (5) the the third goal of this publication is to present a Ornithischia, another well-diagnosed monophy­ plausible scenario for theropod and ori­ letic order, also extant from the Late Triassic gins to justify the classification I have construct-

Parainfraclass Archosauria Cope, 1869 5 Introduction ed. Some aspects of this scenario are undoub­ (Steel 1969, 1970, 1973; Wellnhofer, 1978; and tedly incorrect and stem from my imperfect Charig, Krebs, Sues & WestphaL 1976), the an­ knowledge of theropod and avian anatomy, as nual Bibliography of Fossil , the Rep- well as an outrageously poor fossil record, but tilia volumes of 77ie Zoological Record, the ar­ I do not consider these shortcomings particu­ chosaur volumes of the Fossilium Catalogus, larly important. What is more important is the and various popular "dinosaur dictionaries," paradigm shift that I think is required to under­ were used to construct the initial master list. stand bird-theropod relationships. Succinctly, it Dan Chure, John S. Mcintosh, and I cross­ is that birds did not descend from certain ther­ checked our dinosaur lists when they compiled opod dinosaurs, but rather that theropod dino­ A Bibliography of the Dinosaurs (Exclusive of saurs comprise a series of groups of flightless the Aves) 1677-1986 (Chure & Mcintosh, anim.ik descended from a diversity of primitive 1989); David B. Weishampel and I did likewise gliding and flying birds. This idea is not as bi­ when he was editing 77je Dinosauria (Weisham­ zarre as it might at first seem, as I hope the sce­ pel, Dodson & Osmolska, eds., 1990). As new nario accompanying the discussion of the thero- systematic studies are published, the results are podomorph orders will make clear. incorporated into the list. Through personal The final goal of this publication is to cor­ correspondence, many workers keep me ap­ rect several nomenclatural irregularities I un­ prised of new discoveries and publications, so earthed while recompiling the checklist. Two the actual master list contains some unpub­ generic names turned out to be preoccupied lished names. These I removed from this pub­ and required formal changing, and several spe­ lished version in order to avoid conflicts over cific names needed minor respellings. Two spe­ nomenclatural priority. Taxa whose publication cies of Wealden theropods long (and incorrect­ is imminent (and some whose publication is ly) referred to the genera and Al- not so imminent) are indicated as "to be de­ tispinax required new generic names. Such pe­ scribed." No feasible procedure can guarantee culiarities surface whenever systematic check­ completeness, but the present list is certainly lists are assembled, and I call attention to them more complete than any archosaur list previ­ in a separate section below rather than simply ously published, and it is almost certainly com­ burying them in the list. plete through the 1988. Readers aware of published archosaur taxa that have been omitted from my list are urged MATERIALS AND METHODS to send me references or (if possible) photo­ copies of the publications. Also, despite having The master archosaur list is presently main­ worked on my list for nearly two decades, I tained as a series of documents in WordPerfect have still not been able to verify spellings, au­ 4.2 on a Cordata AT (IBM clone) personal thors' names, and dates of all the included taxa computer. The documents interface with a from their original sources. So I would be most Xerox Ventura 1.0 desktop publishing system, interested in receiving any corrections, and I which automatically formats them and sets will gratefully acknowledge such improvements them in . They are output as camera-ready in subsequent printings of this list. pages through a Hewlett-Packard LaserJet II The present list retains much of the format printer. Additions and corrections to the mas­ of its 1978 predecessor, Mesozoic Meanderings ter list are usually performed through the Ven­ #1. By adding more information about authors tura system rather than WordPerfect, although of synonymies, , localities, and type both systems allow rapid, trouble-free text edit­ and useful referred specimens, I intend to ing. make issue #3 substantially more comprehen­ Compiling and maintaining the archosaur sive. I have already experimented with revised list is primarily library work. All available ar­ formats, and I do not anticipate as long a wait chosaur compendia, such as the appropriate for Mesozoic Meanderings #3 as there was for volumes of the Handbuch der Paldontologie #2.

Introduction 6 Mesozoic Meanderings #2 termined by its morphological diversity as if the HOW TO USE THIS LIST: deleted had never come into existence. CONVENTIONS Linnaean taxa without the para- prefix are mon­ I generally adhere to the typographical and ophyletic (clades). For nomenclatural purpos­ priority conventions set out in the third edition es, parafamilies, paragenera, paraspecies, etc. of The International Code of Zoological Nomen­ should be treated exactly like families, genera, clature (ICZN, 1985), but I also employ certain species, etc under the ICZN. Deciding which abbreviations for brevity. These conventions clades to remove in creating a useful parataxon are explained herewith. is part of the "art" of taxonomy, as is (for exam­ ple) deciding when two species are distinct Terminology enough to warrant separate genera, or when For the purposes of this discussion, a taxon two genera require separate families. One is a set of organisms that includes their com­ guideline I adhered to in creating the parataxa mon ancestor (a "natural group" in "old-fash­ in this table was to subtract as few clades as ioned" terminology); a clade is a taxon that possible, and then only when the removed comprises all the descendants of the common clades encompassed evolutionary novelties that ancestor. A taxon that is also a clade is called would compel classification at a Linnaean rank monophyletic, a taxon that is not a clade is at or above that of the parent parataxon. called paraphyletic. Any other grouping of orga­ For example, the taxon Reptilia is a para- nisms is potyphyletic. In the Linnaean classifica­ class formed by the removal of the clades Aves tion, the taxa are arranged hierarchically in lev­ and Mammalia, which are Linnaean classes, els, and each high-level taxon is completely par­ from the clade Amniota, which is a superclass titioned into taxa at the next-highest level. The within the infraphylum Tetrapoda. As de­ seven canonical levels are kingdom, phylum, scribed herein, the Archosauria is a parainfra- class, order, family, , and species; in be­ class within the paraclass Reptilia and parasub- tween these are often placed such noncanoni- class Diapsida, since it is defined as the clade cal levels as tribe and cohort, as well as subfam­ Archosauria minus the clade Aves. And the ilies, superorders, parvorders, megafamilies, parainfraclass Archosauria contains within it and so forth. But specifying an organism's sev­ the parasuperorder Theropodomorpha and par­ en canonical levels (kingdom and phylum are aorder Theropoda, inclusively smaller parataxa broad enough to be understood from context defined by the removal of the clade Aves. (It and are not usually noted) completely identifies should be noted in this context that Aves does it in the Linnaean system. not include the parafamily Archaeopterygidae, which I place in the suborder Deinonychosau- Monophyletic and Paraphyletic Taxa ria. More on that in the succeeding sections.) The current trend in taxonomy is to arrange that all named taxa be monophyletic. For rea­ Theoretically, every parataxon above the spe­ sons outlined in the next section, I do not think cies level must contain at least one parataxon this is feasible, and my classification retains a of lower rank. The fossil record, however, is number of useful paraphyletic taxa. These are too poor in most cases to identify all included signaled with the prefix para-, as in paragenus, taxa. As I argue in a subsequent section, a parafamily, parasuborder, paraorder, etc. No large number of families, genera, and species species listed here can be identified with any have yet to be discovered and identified within degree of certainty as ancestral to any other the Archosauria. taxon, so the term paraspecies is not needed, al­ Genera and Species though it could be useful in constructing taxon­ Genera (and paragenera) are listed alpha­ omies of other groups. Formally, a paraphyletic betically within each family. Species are listed taxon, or parataxon, may be defined as the dif­ in chronological order within each genus. As a ference between a clade and one or more in­ rule, the author and year of each taxon refer to cluded clades; its Linnaean rank is (usually) de­ the work in which the taxon was originally de-

Parainfraclass Archosauria Cope, 1869 7 Introduction scribed. Genera and species attributed to an noted a kind of informal synonymy. To avoid author within the work of another are denoted confusion with the formal subgeneric notation, by the Latin term vide ("see"); the author of I have separated such "double genera." Thus the taxon precedes the vide, the author and (Pteropelyx) grallipes Lambe, 1902 is year of the attributing work follow it. listed as both Trachodon grallipes Lambe, 1902 The type species of a genus is followed by and Pteropelyx grallipes (Lambe, 1902). the notation "(Type)." It is possible even for a Doubtful Names nomen nudum genus (see Doubtful Names be­ I recognize two kinds of doubtful taxa: nomi­ low) to have a type species, if the species is the na dubia and nomina nuda. A species name only one named within the genus (type by presently thought to be based on material not monotypy) or is the first one named within die diagnostic to die species level is noted as a no- genus. Such "type" species, of course, have no men dubium. A generic name thought to be formal nomenclatural standing. based on material not diagnostic to the generic Recognized species within a genus are al­ level is similarly noted. If a genus is listed as a ways written with the generic name abbreviat­ , then its type species is automat­ ed to the initial letter; species synonyms (see ically a nomen dubium (and die notation no­ below) are spelled out completely to avoid con­ men dubium is unnecessary), but it does not fol­ fusion. A question mark (?) preceding a spe­ low that all species included in a doubtful gen­ cies name indicates that the species is provi­ us are themselves nomina dubia. Those diat sionally or doubtfully referred to die listed gen­ are not could, however, require new generic us. Such question-marked species should be names and/or proper descriptions—a task be­ considered targets for further research and yond the scope of diis paper. The more severe may represent as-yet-undescribed new genera. term nomen vanum ("empty name") sometimes Occasionally I was able to refer such species to seen in taxonomic studies is redundant with die better genera myself (as I did, for example, term nomen dubium and is not employed here. with Caudocoeuts sauvagei and Tylocephaie bex- elli in Mesozoic Meanderings #1). If such refer­ Nomina nuda are names of taxa published ences create new combinations of generic and without descriptions. These often appear in fau- specific names, I denote them conventionally nal lists that refer to work in preparation, or as as "n. comb." names of convenience for specimens to be de­ scribed. Popular news articles on paleontology Generic and specific names enclosed in quo­ occasionally publish names ahead of their for­ tation marks represent published names of con­ mal descriptions. In this list, if a taxon has venience for undescribed taxa. They should be been formally described, then its name is attrib­ considered nomina nuda (see Doubtful Names uted to the author and year of the description; below). earlier usages of the name, which are all nomi­ Subgenera, subspecies, and varieties have oc­ na nuda, are listed as synonyms. In cases where casionally been described within archosaur gen­ a name simply has no published description, era and species, but as a rule I consider the die name is attributed to the earliest user as a range of variation in fossil vertebrate taxa to be nomen nudum. too poorly known to warrant such fine subdivi­ Some workers (incorrectly) regard as nomi­ sions. In those few instances where the subgen­ na nuda taxa possessing inadequate descrip­ era seem distinctive, I have raised them to the tions instead of simply no descriptions. I con­ generic level; otherwise I have listed tliem sider myself incompetent to judge the adequa­ among the species synonyms. A subgeneric cy of a published description, and I employ the name is conventionally written in parentheses term nomen dubium for such taxa. Also, al­ between generic and specific names; a subspe- though a picture might be worth a thousand cific name is conventionally written after the words, I regard a name used solely in die cap­ specific name. Varieties are denoted by "var." tion of an illustration depicting a specimen— In older works, a generic name in parentheses following another generic name sometimes de­

Introduction 8 Mesozoic Meanderings #2 the quality of the illustration or the specimen nomen dubium. Notes explain the situation in notwithstanding— a nomen nudum. such cases. Synonyms and Renamings Respellings and Misspellings Synonyms of genera are denoted with equals The original spellings of the names of gen­ signs ( = ) and listed in alphabetical order fol­ era and species are used wherever possible. lowing the presently accepted name of the gen­ The ICZN specifies, however, that an original us. Species synonyms (also denoted with equals spelling in which an adjectival specific name signs) are listed in chronological order follow­ disagrees with its generic name in gender must ing the presently accepted species name. Re­ be respelled correctly once the error is noticed. namings of a species are listed alphabetically Similar rules also apply to other kinds of im­ following the original name of the species. If properly formed specific names, such as hono­ the presently accepted name of a species is it­ rific specific names written as singular when self a renaming, then its first listed is more than one person is to be honored. Origi­ always its original name, followed by any other nal spellings that have been thus corrected, ei­ renamings. In a renaming, the author and year ther here or elsewhere in the literature, are are those of the original name enclosed in pa­ flagged with an asterisk (*). The corrected rentheses; this notation unambiguously identi­ spelling immediately precedes the original spell­ fies a renaming in this list. As I was preparing ing. Into the category of respelled names also this paper for publication, however, it occurred fall names originally coined with diacritical and to me that it would be more useful to provide punctuation marks, such as diereses, hyphens, the earliest reference for each renaming, rather and umlauts. The ICZN (1985) rules that such than just to repeat the original author and year. names must be spelled with the marks deleted, The ICZN provides a formal notation for doing except that German vowels with umlauts are to this: the author and year of a renaming are writ­ be respelled with an e immediately following ten after the parenthesized author and year. the vowel. I have followed this rule in all cases. With a few exceptions, such as among the para- Misspelled generic and specific names suchians, I had no time to implement this con­ abound in the literature, most frequently as ty­ vention here, but I will do so as completely as pographical errors, particularly in papers writ­ possible in Mesozoic Meandering? #3. ten in non-Latin alphabets. Compiling these is Obviously, a nomen dubium or a nomen nu­ a project generally lacking in scientific interest, dum cannot enter into formal synonymy with and I have not striven for completeness. Some­ another taxon. Nevertheless, it is often possible times, however, misspellings find their way into with some degree of reliability to pigeonhole the popular literature, so it does seem neces­ doubtful taxa into taxa that are better estab­ sary to point them out. I was more prone to in­ lished. In this list, such pigeonholing—not for­ clude bizarre misspellings than names with mal synonymy—occurs in all cases in which a mundane single-character errors, and to pursue doubtful name is listed as a synonym of another all the misspellings of names that have been taxon (which may itself be a nomen dubium). misspelled in many different ways. Also, I My position on nomina dubia is not that the catalogue generic-name misspellings more com­ taxa are worthless but that we have insufficient pletely than specific-name misspellings. Occa­ information to assess their worth; it occasional­ sionally a misspelled name will be the correct ly happens (e.g., with the genus ; spelling of a different genus or species. Such Currie, 1987) that new discoveries and restud- cases are a potent source of confusion, and I ies erase the "dubium" from the "nomen." have included them in the table whenever I In cases where synonymizing a nomen dubi­ have discovered them. um with another taxon could result in the alter­ All spelling and typographical errors are tab­ ation of a widely accepted name, however, I ulated among the legitimate renamings with the avoid the pigeonholing entirely and isolate the conventional notation "[sic]," a Latin term meaning "there," in the sense of "as written

Parainfraclass Archosauria Cope, 1869 9 Introduction there." The same misspelling sometimes ap­ synonym of another genus in the family, as long pears in more than one paper; I list only the as the material that defines the genus is dia­ earliest appearance of a misspelling known to gnostic to the family level. In cases where more me. than one genus in a family is a family-name eponym, rules of priority dictate that the fami­ Preoccupied Names ly's name must be the eldest name formed Preoccupied generic names are denoted by from any included genus; the other names then having two attributions separated by a slash (/). become junior synonyms. As with genera, it The first attribution supplies the author and sometimes happens that the eldest name for a year of the archosaur genus, the second the au­ family has become obsolete from disuse. In thor and year of the earliest use of the name. such cases, I call the eldest synonyms nomina There are no preoccupied species names oblita and conserve the best-known family among the archosaurs, but every so often refer­ names. All synonyms of family names are listed ring a species to a different genus creates a alphabetically following the accepted family new combination identical to a previously creat­ name. ed species name. In such circumstances, I sepa­ rate the two attributions with "non." I also use Because most archosaur families contain this term when definitive material referred to a only a few genera, which seldom fall into well- species is separated from it to define a new defined subsets or lineages (ceratopsid genera species. For example, Thulborn (1970) rede- are an exception; hadrosaurid and lambeosau- scribed the species Fabrosaums australis Gins- rid genera may be others), I eschew categories burg, 1964 using good skeletal material that in between family and genus. Nevertheless, ar- Galton later (1978) removed into a new genus chosaurian subfamilies have been defined fairly and species, Lesothosaums diagnosticus. This is frequently. I simply list them among the syno­ reflected in the list by showing Fabrosaums au­ nyms of the families in which they have been in­ stralis Thulborn, 1970 non Ginsburg, 1964 in sy­ cluded. In one case (Lewisuchidae) I thought it nonymy with Lesothosaums diagnosticus. necessary to raise a subfamily name to the level of a full family, and I demoted a superfamily Conserved and Obsolete Names (Chaoyoungosauroidea) to a family (Chao- If a generic or specific name remains uncit- youngosauridae)—a change of no conse­ ed by zoologists (except in faunal lists and taxo- quence, since both names are still nomina nuda. nomic indexes) during the 50 years following Attributions of family-level names are al­ its creation, it is considered obsolete and is ways to the first publication within a level, not known as a nomen oblitum. It is then no longer necessarily to the earliest usage of the name. eligible under the rules of priority to act as a For example, the family Tyrannosauridae was senior synonym of a later name, and it cannot named by Osborn (1905) to accommodate his preoccupy a later usage of the name for a dif­ new genus Tyrannosaums. As presently consti­ ferent genus or species. Suppressing a nomen tuted, the Tyrannosauridae also includes Lei- oblitum usually requires a special ICZN ruling, d/s tooth genus Deinodon, for which Cope often when a well-known name is threatened (1866) erected the family Dinodontidae. Be­ with replacement by an obscure potential se­ cause the name Dinodontidae is based on a nior synonym. The "rescued" name is then tooth genus, it fell out of use (even though called a nomen conservandum, or conserved most of the Deinodon type teeth definitely be­ name. Instances involving such names are suita­ long to a tyrannosaurid), and it has become a bly annotated in this list. nomen oblitum ineligible for senior synonymy of Tyrannosauridae (though no formal ruling Families and Subfamilies about this has been made to my knowledge). The ICZN mandates that a family-level The spelling Dinodontidae was emended to name must be derived from an included genus. Deinodontidae by Brown (1914), and Matthew Although it is not good taxonomic practice, the & Brown (1922) divided the Tyrannosauridae genus may even be a nomen dubium or a junior into two subfamilies, Deinodontinae and Tyran-

Introduction 10 Mesozoic Meanderings #2 nosaurinae. Conventionally, the two subfamilies are plenty of already-available names for high­ would be attributed to Cope, 1866 and Osborn, er archosaur taxa in the literature. 1905, respectively, but in this list I supply the Naturalists display considerable inertia when earliest publication within a level, so I attribute it comes to accepting changes in taxonomic sys­ them to Matthew & Brown, 1922. All these re- tems that they have worked with their whole namings and subfamilies are listed as synonyms lives, and I do not expect the system con­ of Tyrannosauridae Osborn, 1905. structed here to be adopted overnight. But I be­ lieve that the incrementally less cumbersome Higher Taxa and intuitively more obvious usages advocated Families, parafamilies, and higher taxa are here, as exemplified by "paraorder Theropoda, listed in systematic order within their parent suborder Carnosauria," will eventually super­ taxa. Since each taxon contains its common an­ sede die more traditional usages, such as "or­ cestor, the taxa can often be sorted, after cladis- der Saurischia, suborder Theropoda, infraorder tic analysis, by the relative positions of their an­ Carnosauria." cestral nodes in die of their parent taxon. Where such sorting is ambiguous {e.g., in Taxa incertae sedis a clade with two equivalent subclades), I list Sometimes lower-order taxa defy classifica­ the taxon with die geologically earliest-known tion into higher taxa. A type specimen may be common ancestor first. largely incomplete, or it may represent a spe­ The families in this list are organized into cies so different from related forms that it re­ higher taxa according to my own views of tradi­ quires new higher taxa that the describer feels tional taxonomy, cladistic analysis, and archo- unready to create. For such problematic taxa, saur phylogeny, as outlined in the Taxonomic nomenclatural procedure provides a special cat­ Considerations and Archosaur Phylogeny sec­ egory denoted by appending the Latin term in­ tions which follow. These views broadly agree certae sedis ("of uncertain position") to the with those of most other workers, because they name of die lowest taxon in which the proble­ are derived from their work; but even users matic forms are certainly classifiable. For exam­ who utterly disagree with my views should still ple, theropod taxa that cannot be placed in any find this list serviceable. of the listed suborders are categorized as The­ The nomenclature of taxa above the family ropoda incertae sedis; sauropod taxa not classifi­ level is not governed by the ICZN, but in those able in any of the listed families are categor­ instances where a taxon has been given more ized as Sauropoda incertae sedis; ceratopsid than one name, I employ either the eldest taxa not classifiable in eidier of the two ceratop­ name or the one in commonest use. I do not sid subfamilies are categorized as Ceratopsidae list synonyms for higher taxa, because taxa incertae sedis; and so forth. I have not always above the family level are more closely wedded done this consistently, preferring, for example, to their authors' taxonomic philosophies than to refer genera provisionally to established fam­ to the anatomical details of the included gen­ ilies if there is at least some chance that the re­ era and species. Consequently, higher taxa tend ferral is correct. This, I think, conveys more in­ to overlap rather than coincide, and they are formation about the problematic taxa than not anchored to type taxa at lower levels, so sy­ simply throwing diem into an incertae sedis bin. nonymies among higher-level taxa are difficult Occasionally workers will refer a taxon to to establish. In particular, cladists employ high­ die next higher taxon incertae sedis when they er taxa that are clades, which fail to agree even mean a provisional referral. For example, one in principle with the taxa employed by traditio­ might refer a genus to a family incertae sedis nalist taxonomists. I avoided using names even though die family has not been parti­ coined specifically for clades (such as Tetanu- tioned into subfamilies. This, however, is a mis­ rae, , and ) unless use of the incertae sedis notation. The incertae I saw a compelling need for such taxa. There sedis category stands in place of the next higher category in which a taxon could be classified.

Parairtf raclass Archosauria Cope, 1869 11 Introduction Provisional referrals in this table are always thodologies, I will also carry trace taxa in my noted as such. table. Ichnotaxa, Ootaxa, and Trace Censuses Archosaur footprints, eggs, and other trace Genera and species are counted within each fossils can tell us an enormous amount about family, and families, genera, and species are their makers' behavior and diversity. A large lit­ counted within each suborder and order. erature about trace fossils, complete with taxon­ Doubtful taxa (usually nomina dubia) are in­ omies parallelling that of the archosaurs' physi­ cluded in the main counts but are also counted cal remains, has arisen, with which I have only separately, not counted are synonyms, nomina just begun to familiarize myself. Unfortunately, nuda, and genera and species to be described. synonymies and misidentifications abound in I do, however, count established species includ­ the earlier works, and I have not had the op­ ed in genera that are nomina nuda or to be de­ portunity to look at the taxa comprehendingly scribed. Parataxa are counted along with the enough to tabulate them. The best and most re­ others. cent compilation of dinosaur trace taxa is in Crocodilian taxa that have found their way Chure & Mcintosh, 1989; other entries into the into this table are counted, but the totals are literature may be found in Gillette & Lockley, not included in the census for superorder eds., 1989 and Thulborn, 1990. I have started Thecodontia because the entire order Croc- to acquire copies of trace-taxa articles for my li­ odilia is not listed. Taxa in the Excluded Taxa brary, and once I become familiar with the me­ section are, of course, not counted either.

introduction 12 Mesozoic Meanderings #2 Taxonomic Considerations

HEN I PUBLISHED my first table of ar- characters, in order to discover which of a rath­ Wchosaurian taxa, cladistic analysis of the er large set of possible phylogenies is most like­ archosaurs was in its infancy. Recognizing the ly to be correct. As such, cladistic analysis is onset of a "new wave," I acquired several (among other things) a rigorous restatement of books (Cracraft & Eldredge, eds., 1979; El- Cnpe/s Rule r"nrfianisms-46ad-to--exQlve from dredge & Cracraft, 1980; Schoch, 1986; and generalized forms to spedalized_forms") and others) to guide me through its intricacies, and DoUtfs^il^^ .("anatomical .parts lost through I soon discovered one particularly biting pas­ evolution are not restored, only replaced"). sage (Boucot, 1979): "After stripping away the NeitheT™oT"these "laws" is absolutely true, of jargon of 'morphos,' 'apos,' 'plesios,' 'syns,' course; they are simplified descriptions of two 'character states,' and whatnot, I can only con­ commonly observed evolutionary trends. Their clude that 'phylogenetic systematics,' or 'cladis- significance lies more in their breach rather tics' (call it what you will), is nothing more or than their observance, for it is the breaches less than old-fashioned taxonomic classification that are rare and phyletically useful. so plastered over with jargon as to be unrecog­ Taxonomic papers using cladistic analysis nizable to the casual reader." tend to be organized alike. The reader is pre­ While I don't think is that awful, I sented with a character matrix for the taxa un­ do view it primarily as a method of discovering der consideration. After some discussion, the whether the groupings in one's taxonomy are paper concludes with a tree diagram, or clado­ monophyletic or not. It can also—sometimes— gram, showing the relationships among the taxa identify previously unsuspected evolutionary derived from the character matrix. The impor­ trends, although consygnjigjthajaumbi^coXj^ tant point is that there is little more informa­ tion in the cladogram than already exists in the various archoMurjgroups^^ character matrix. The cladogram is simply a r^^jmgrw^^^^ja^ss^m^- On the more comprehensible arrangement of the data whole, nonciadistic and precladistic taxono- in the matrix, designed to allow the creator to mists seem to have done quite well elucidating pick out characters that are homologous, homo- phytogenies with just the traditional methods plasious, reversed, and so forth. Character ma­ and, perhaps, a modicum of common sense. trices with more than a couple of hundred The fundamental principle of phylogeny is entries (say, 10 taxa by 20 characters) are usual­ that organisms possessing large enough suites ly too large to analyze manually in a reasonable of characters in common do so because they time, particularly when several different cladis­ are descended from common ancestors, not by tic algorithms are being compared, so a com­ coincidence (/'.«., convergence). This is because puter generates a "most parsimonious" clado­ the space of possible morphologies or molecu­ gram: one with the smallest number of viola­ lar sequences is so immense that the chance of tions of Cope's Rule and Dollo's Law, for ex­ the same suite of characters arising within unre­ ample. (This, incidentally, tends to place the im­ lated taxa is vanishingly small. Cladistic analysis primatur of mathematical precision on the pro­ at its best strives to describe such suites of cess, a phenomenon with which I, as an erst-

Parainf raclass Archosauria Cope, 1869 13 Taxonomic Considerations while computer scientist, am quite familiar. ry of evolution, simply by the possession of Fortunately, I am also familiar with its inverse: shared characters: synapomorphies). "garbage in, garbage out.") The Linnaean system owes its success to the There are two subtle effects that need to be fact that extant organisms do not form a contin­ mentioned with regard to the algorithms that uum of morphological types but cluster into dis­ convert character matrices into . crete groups with well-defined suites of charac­ Fjrst^-not-ail^characters should_jbe__gventhe ters, between which transitional types can sel­ s^niejiKeight^LcahjwejJm^^ne that reversals dom be identified. The clustering pattern, am­ of minor anatomical features, sucfi~as*process- ply explained by Darwinian theory, provides es and rami of cranial "*^T3Sr~wo5Td" occur the natural divisions among the taxa as well as moFe ffeqirenfly'lind eaHly,IIEifl_rsyersak of the hierarchy in which to arrange them. The major anatomical -features..^uch as carpjil or name of each taxon is a convenient shorthand tarsal structure. Second, an organism's ecologi­ for the suite of characters common to the orga­ cal nicneTends to restrict the space of possible nisms classified in the taxon, and this conveni­ morphologies, making convergence and homo- ence is one of the outstanding features of the plasy more likely between organisms of similar Linnaean system. size or lifestyle. For example, large carnosaurs When only extant organisms are to be and sauropods both exhibit hyposphene-hypan- named and classified, it is conceptually straight­ trum articulations between dorsal vertebrae, forward and even desirable to convert the Lin­ which is a size-related character, not a synapo- naean system into a cladistic system. Linnaean morphy that indicates close phyletic relation­ species are taken to be the lowest-level clades; ship. There is no really good way to assign then genera are defined as clades containing weights to such characters (Schoch, 1986: 116- the species, families as clades containing the 123), and one can only hope that the balance genera, and so on. Some Linnaean taxa, such of other characters in one's taxonomy will filter as the paraclass Reptilia, turn out not to be out any misleading phylogenies due to them. clades themselves, but they can be subdivided Otherwise, there remains little to complain or subsumed into taxa that are. It is easy to in­ about with this methodology. It seems to me clude common ancestors in the clades, because that die faults lurking in cladistics lie primarily they are entirely hypothetical constructs not with how characters and taxa are defined, rath­ found among the extant taxa. The cladistic er than with the algorithms and procedures movement seeks to ensure that all Linnaean used to transform a character matrix into a cla- taxa are either diagnosed as clades or eliminat­ dogram. That is, I have less complaint with ed, in keeping with the precept that clades are how cladograms are constructed than with how the only real taxonomic entities. they are subdivided into taxonomies. The Ancestral-Taxon Problem Both Linnaean and cladistic systems suffer when they are extended to include extinct as THE PROBLEMS OF CLADISTIC well as extant organisms. For example, a natu­ CLASSIFICATIONS ralist might discover a fossil that he or she be­ In a purely cladistic classification, all die lieves is the actual ancestral form of the entire taxa are clades, and hierarchy is determined by class Aves. What name is to be given to this set inclusion rather than by an artificial system creature's species? In the Linnaean system, the of typologically defined levels. Cladists assert, naturalist would simply bestow a binomial quite correctly, I might add, that clades are the upon it, and probably give it its own family and only "real" phyletic sets, in the sense that they order as the most primitive bird taxon. But in a require no typological boundaries to be drawn cladistic system, the species would be an inad­ among them. Membership in a clade is deter­ missible paraphyletic taxon unless it included mined by descent (or, in the absence of a theo­ all birds; that is, die species itself could only be named Aves — or Aves aves if a strict binomial

Taxonomic Considerations 14 Mesozoic Meanderings #2 is required—and all later birds would have to clades formed by the successive exclusion of be considered its sub-sub-...-subspecies. Some each of the aforementioned genera are named cladistic taxonomies avoid this problem by de­ and diagnosed: Dryomorpha for all - claring the new species to be the closest possi­ tians except Tenontosaums; Ankylopollexia for ble outgroup to, or the lowest possible ingroup all dryomorphans except Dryosaums; Styracc- of, the descendant clade, but this would deny sterna for all ankylopollexians except Campto- the ancestral status of the species that the saurus; Iguanodontoidea for all styracosternans naturalist wished to convey. I consider this to except Probactrosaums; and be untenable taxonomy: an extreme case of the for all iguanodontoideans except Iguanodon, Ancestral-Taxon Problem. that is, Hadrosauridae plus Ouranosaums. The In the slightly modified Linnaean system families in which those genera were traditional­ used here, the hypothetical ancestral species ly classified are largely scrapped. Similar series would be given a Linnaean binomial and would of genera are found in the Pachycephalosauria be designated a paraspecies. In its role as the and the Ceratopsia. Taxa in such series are ancestral avian species, it would be placed at called stem-group taxa (Thulborn, 1984; the root of its own paragenus, which would be Schoch, 1986: 25), since they connect a root placed in turn at the root of a parafamily and a node (in this case, of the clade ) paraorder, and ultimately at the root of the en­ with a crown group (in this case, Hadrosauri­ tire class. The hypothetical parent species from dae). The proliferation of long sets of named, which the ancestral bird was descended — serially nested stem-group clades I call the which, by consensus of dinosaurologists and pa- Stem-Group Problem. leoornithologists, would not be a bird but a This problem has two ramifications. First, theropod—would itself be designated a para­ such nested higher-level taxa are of doubtful species within a paragenus of a parafamily of utility. We all agree that the history of life is of the paraorder Theropoda. surpassing complexity, but it is neither neces­ Admittedly, this is an extreme case. Provably sary nor desirable for our taxonomic systems to ancestral species are rarely, if ever, encoun­ be equally intricate. One of the great virtues of tered in the fossil record, which is why cladistic the Linnaean system is that it simplified and taxonomies seldom face this challenge. But systematized the bewildering array of orga­ higher-level taxa in which hypothetical an­ nisms that inhabit and inhabited the earth. It is cestral species could be classified are quite difficult to imagine dinosaurologists pondering abundant, as they should be if we believe that whether iguanodontian fossils they have discov­ species arise from other species. ered should be called dryomorphic, ankylopol- lexian, or styracosternal, and I can see no bene­ The Stem-Group Problem fit in creating a hierarchy comprising as many In the system used here, a parataxon is de­ nested higher-level taxa as there are genera in fined as the difference between a clade and it. Such a classification is as inefficient as a fac­ one or more included clades. In a strictly cladis­ tory with six workers and five managers. tic taxonomy, parataxa are inadmissible, and as And second, the reader is invited to consid­ a result similar taxa within a clade sometimes er what could happen to the above carefully fall into a series of outgroups converging on constructed iguanodontian classification after a the clade or clades that would have been re­ few more genera are described, or when anoth­ moved to make the parataxon. Sereno's (1986) er taxonomist {e.g., Horner, 1988, 1990) propos­ cladistic classification of the Ornithischia pro­ es a different arrangement of some of the same vides a number of examples. In his Figure 6, genera! Stability of the higher taxa is a desira­ the genera Tenontosaums, Dryosaums, Campto- ble trait of the Linnaean system that is not par­ saurus, Probactrosaums, Iguanodon, and Ouran- ticularly evident in cladistic systems. osaurus are shown as iguanodontian genera converging successively toward the family Had- I avoid this kind of microtaxonomy by indi­ rosauridae. Within the Iguanodontia, all five cating ancestry and descent in a general way with a suitable choice of parataxa. For exam-

Parainf raclass Archosauria Cope, 1869 15 Taxonomic Considerations pie, of the iguanodontian taxa under discus­ die proliferation of hierarchic levels in cladistic sion, I list Tenontosaums provisionally within taxonomies die Too-Deep-Hierarchy Problem. the parafamily Hypsilophodontidae, Dryosau- To avoid the Too-Deep-Hierarchy Problem, rus in the family Dryosauridae, cladisdc taxonomists sometimes advocate do­ in the family Camptosauridae, and Probactro- ing away with the Linnaean hierarchic levels en­ saums, Iguanodon, and Ouranosaums in the tirely (e.g., by replacing them with numerical parafamily Iguanodontidae. I consider it likely identifiers or by using various typographical that the dryosaurids, camptosaurids, and iguan- conventions; Schoch, 1986: 255-263). The sys­ odontids originated among the - tem I use here solves this problem automati­ tids, and virtually certain that the hadrosaurids cally by restricdng the Linnaean levels to a and lambeosaurids originated among the iguan- manageable few, and by listing included genera odontids, even though we cannot point to spe­ arbitrarily in alphabetic order. Suprageneric cific ancestral genera in the families (Sues & parataxa are listed ahead of their descendant Norman [1990], however, consider the Hypsilo­ taxa. I have tried to avoid subdividing taxa un­ phodontidae monophyletic, a to necessarily and using suprageneric taxa contain­ the Iguanodontia; my idea of a hypsilophodon- ing only one genus (this, of course, has not tid is less restrictive than that). More detail been possible in all cases). The most useful than this is, in my opinion, not warranted in a classification, it seems to me, is one that is con­ taxonomy involving so few genera, and particu­ ceptually simple and does not attempt to strait- larly not when die relationships among the taxa jacket users with its creator's philosophy or are still being vigorously debated (Cooper, phylogeny. 1985; Horner, 1988, 1990; Sues & Norman, 1990; Norman & Weishampel, 1990). The Too-Many-CIades Problem The Too-Deep-Hierarchy Problem is a par- The Too-Deep-Hierarchy Problem ticular case of tJie Too-Many-CIades Problem. The Stem-Group Problem is a specific in­ Most cladograms are, or strive to be, binary stance of a more general problem that con­ trees; that is, graphs in which the branch nodes fronts cladistic taxonomies. In the iguanodon­ lead to exacdy two other nodes. This reflects tian example above, Sereno categorizes the die idea that in any evolutionary lineage only Iguanodontia as an infraorder and the Hadro- one new taxon breaks away at a time. Clado­ sauridae as a family; the five serial clades in be­ grams with nodes that branch to more than two tween the Iguanodontia and the Hadrosauridae other nodes are considered unresolved: there is are categorized at Linnaean levels in between not enough information to decide the order in die infraorder and the family: gigafamily Dryo- which the taxa at the polychotomous nodes morpha, megafamily Ankylopollexia, grandfami- formed. A moment's reflection will show that a ly Styracosterna, hyperfamily Iguanodontoidea, fully resolved cladogram with N terminal nodes and superfamily Hadrosauroidea. Of these lev­ always has N-1 branch nodes, one of which is els, only the superfamily is in general use by die root; an unresolved cladogram always has traditional taxonomists; die other levels were fewer. This table lists over 600 archosaur gen­ invented by cladists (Schoch, 1986: 259). When era, so a fully resolved cladogram of these gen­ more iguanodontians are discovered, more era would have at least 600 branch nodes, that levels may have to be intercalated among die is, at least 600 potentially nameable supragener­ gjga-, mega-, grand-, hyper-, and superfamily ic clades. Even if half the archosaur genera are levels. (I can imagine having to develop a taxon­ based on incomplete material that does not omy just to keep die prefixes straight: Sereno's allow die cladogram to be fully resolved, this levels are ranked differendy from those listed still leaves 300 possible clades. Since clado­ by Schoch!) The history of life being as compli­ grams are determined objectively by shared cated as it is, I can even imagine die number of characters, tliere is no reason to favor some levels in cladistic taxonomies eventually exceed­ clades witi names and not otliers. This is un­ ing our ability to coin names for them. I call doubtedly why cladistic taxonomy has given tra-

Taxonomic Considerations 16 Mesozoic Meanderings #2 ditional taxa unfamiliar diagnoses (such as Or- B joined to a common root. But this cladogram nithosuchia and Pseudosuchia in Gauthier, does not specify the phyletic relationship be­ 1986), and has afflicted us with an undesirable tween A and B uniquely. Species B could be an­ proliferation of named suprageneric taxa (and cestral to A; they could both be descended with taxa that have pseudo-names such as "Un­ from a third species, C, omitted from the clado­ named Taxon Including Ornithosuchidae, Lago- gram; or they need not even be closely related. suchus, Pterosauria, Herrarasauridae* [sic], Or- All these situations result in the same clado­ nithischia, Sauropodomorpha, and Theropoda" gram, because in this case only one is possible. (Gauthier, 1986a: 151]). Increasing the number of species increases the In this table, I employ parataxa to sidestep 'number of^^fckj^tegiains^bunt also'tn- the Too-Many-Clades Problem. A taxon or par- creases the number of ways the cladograms_can ataxon comprising serially listed subtaxa func­ mo^d^£EZ£pS(Ae^~^ylf^^L..^^e^y If tions as an unresolved node in a cladogram, even the trivial two-taxon cladogram models thus keeping the number of named supragener­ phylogeny ambiguously, I can only imagine the ic taxa manageable and allowing a variety of dif­ number of different ways more complicated cla­ ferent interpretations of the phyletic relation­ dograms could be misinterpreted. (This is what ships among the genera. I think has happened in theropod-bird phyloge- nies; the cladograms are generally correct, but The Species-as-Points Problem the phytogenies have been improperly mod­ In cladograms, species, and supraspecific eled. More on this in the Dinosaur Phylogeny taxa whose characters are not germane to the section.) cladistic analysis, are treated as points —the It might be best to think of cladograms as re­ end nodes of the cladograms. But many species lating specimens rather than species and higher cannot be reduced to phyletic points, because taxa (among dinosaurs, many species of which they have speciated. That is, some of their char­ are represented by solitary type specimens, this acters were lost, others were added, and still is not very far from reality). But all that is real­ others changed through the passage of time. ly needed is to acknowledge that the interesting The reason species can be characterized at all action in a cladogram takes place on the is that their characters change on time scales branches joining the nodes rather than at the considerably longer than the lifetime of an in­ nodes themselves. Zero-dimensional nodes can­ dividual researcher—or, for that matter, the not change or speciate, but one-dimensional span of recorded history. For all practical pur­ curves can. By indicating which branches repre­ poses, species change continuously and con­ sent which taxa in a cladogram, we can for all stantly, though the rate of change at any par­ practical purposes sift out the incorrect phylog­ ticular time may be quite rapid or very slow. enies—or at least focus on the places in a phy­ The changes can involve the entire population logeny where our understanding is incomplete. () or only a reproductively isolated subpopulation (). Changes noticea­ Species do not exist as objective entities; ble over the span of time required to lay down only populations of organisms do. Certain pop­ a geological stratum are considered rapid; ver­ ulations of organisms interbreed freely among tebrate species do not usually change on time themselves and not with other populations; this scales of less than a million years. phenomenon leads to the concept of a biologi­ cal species, and in turn to the idea that such an Because species and some higher taxa are entity can be defined, named and studied (Otte represented as zero-dimensional points in a cla­ & Endler, eds., 1989). Biological species almost dogram, the topology of cladograms does not always comprise individuals with similar geno­ lend itself readily to diagramming changes in types and phenotypes; at least, they fall into a species. For example, let A and B be two spe­ small number of such sets. This means that a cies, with A the immediate ancestor of B. named biological species can be associated There is only one possible cladogram relating with a set of typological attributes, and that A and B: the trivial cladogram showing A and these attributes can in turn be used to charac-

Parainfraclass Archosauria Cope, 1869 17 Taxonomic Considerations terize the species. For extant species, these at­ phenomenon that leads to the morphological tributes .can Jbe morphological, behavioral, aria gaps between related taxa, and which allows us molecular; byjJbxJassjHonns, they are almost to classify species in a hierarchic system at all. exclusively morphological. It is the changes in In traditional taxonomies, higher-level para- these attributes that we track when we say that taxa are defined typologically; the boundaries species change and speciate through time. of a taxon are set by a consensus of the natura­ Unicellular organisms multiply by dividing, lists who work with it and related taxa. When a and after the act of mitosis it is impossible to fine line must be drawn between two taxa, con­ decide which individual was the parent. Specia- sensus is the only way to do it. It may sound tion is an analogous process, but it is almost al­ terribly arbitrary and subjective, but it is no ways possible, at least theoretically, to decide more arbitrary than identifying a species by its which is the parent species and which is the attributes and noting the appearances of new daughter. What effects this decision is the con­ species as these attributes change. tinuity of the characters before and after the In short, I agree with Mayr and Simpson, as speciation event: The species that retains more cited by Schoch (1986: 262), that although a of the primitive attributes is considered the par­ classification should be based to some degree ent species. According to Mayr (1942), specia­ on the hypothesized evolutionary history of the tion occurs when a population of organisms be­ organisms, it should serve as a convenient infor­ comes reproductively isolated from a larger mation retrieval system about the organisms as population long enough for anagenesis to ren­ well. der interbreeding between the populations im­ Philosophically, perhaps the worst flaw in possible. In such a circumstance, the relative cladistic taxonomies is this: If clades make up sizes of the populations may be sufficient to es­ the only taxa, then there is ultimately no real tablish which species is the parent. But regard­ novelty in the process of evolution. Birds and less of how parenthood is ultimately estab­ mammals are not new classes of vertebrates, lished, it is important to note that the parent they are merely derived archosaurs and therap- species is a paraphyletic taxon, because it no sids. New phyla can no longer appear, because longer includes all of its descendants. all the phyla that can be arose at or just after Higher-level taxa give rise to other taxa in the revolution, and all the life forms an exactly analogous way. A species within a su- on earth ever since have fallen into subclades praspecific taxon may speciate, and the daugh­ of these. If what determines families, orders, ter species may again speciate, until a species and classes is remoteness of ancestry rather appears in which enough characters have than form and function, then humans, mam­ changed that it can no longer be considered mals, birds, dinosaurs, and are ultimate­ part of the original supraspecific taxon. Like a ly nothing more than large, highly derived, co­ parent species, the parent parataxon can con­ lonial microbes. While this viewpoint can be de­ tinue to exist and give rise to more new taxa, fended, I find it, and the cladistic taxonomies some within the taxon and others perhaps out­ that spring from it, ultimately sterile. A clade, side. used as a taxon, becomes a prison in which Although species can be considered as be­ groups of organisms are forever trapped, no ing in a continuous state of anagenesis, specia­ matter how much their descendants may tion events occur rather rarely. In between change from their ultimate ancestor; but a para­ such events, a species may change considerab­ taxon is a wellspring from which, every so often ly, so that a later daughter species may be mor­ in the history of life, organisms and taxa arise phologically quite different from an earlier that are genuinely new. daughter species of the same parent. It is this

Taxonomic Considerations 18 Mesozoic Meanderings #2 culiar that the traditional dinosaurian orders UNNAEAN TAXA AT THE ORDINAL have not followed the pattern of the other LEVEL groups enumerated above. Whereas there are There are no objective rules for classifying some two or three score orders of birds, mam­ organisms within the Linnaean hierarchy. Al­ mals, fish, and insects, the number of dinosaur though one might define a species by overall orders is two. Why should this be so? similarity to a type specimen or by the ability of Perhaps dinosaurologists have been more the organisms in the species to interbreed, conservative than mammalogists, ornithologists, there is no algorithm to decide when two simi­ ichthyologists, or entomologists, austerely classi­ lar species belong in different genera or when fying their objects of study into two orders de­ they are similar enough to remain in the same spite a diversity requiring more. Conversely, it genus. Nor are there algorithms for deciding may be that students of extant forms have given when two genera belong in different families, their fields grandiose dimensions by splitting two families in different orders, and so forth. their taxonomies into more orders than neces­ These decisions are made ad hoc by naturalists sary. I believe, however, that the natural scienc­ acting on their personal ideas of similarity and es contain enough built-in checks that the latter common descent. As noted previously, this is alternative is untenable; the present work is an part of the "art" of taxonomy. Successful taxon­ attempt to undo any effect ascribable to the omies are those that make the most sense to former. their users and, as a consequence, withstand a The situation changes somewhat when all test of time. I need not mention that this ar­ are taken into consideration, not just bitrariness leads naturally to the notion that su- the dinosaurs. Reptilian diversity at the ordinal praspecific Linnaean taxa are entirely artificial level attained a maximum during the Triassic and have no objective meaning. (cf. graphs in Padian & Clemens, 1985), when In particular, mammals, including extinct approximately 15 orders were known to be ex­ forms, are presently classified into 44 orders tant. But most of those orders became extinct (listed in CarrolL 1988). The class Aves, which at or just before the Triassic-Jurassic boundary, dominates aerial environments much as mam­ and they were seemingly not replaced by a radi­ mals dominate terrestrial environments, is clas­ ation of new orders comparable to that at the sified into 35 orders (listed in Carroll, 1988, ex­ beginning of the Triassic for the reptiles and cluding Archaeopterygiformes), and the class the for the mammals. Padian and Osteichthyes — which has dominated aquatic en­ Clemens indicate a marked decline in ordinal- vironments from at least the through level diversity and origination of new orders the Recent—is classified into no less than 62 or­ among the reptiles from the ders (listed in CarrolL 1988; the Camp, Welles through at least the mid-Cretaceous. I believe & Green bibliography [1953] lists 70). Finally, this "decline" is at least partly artificial, the re­ the class Insecta, which dominates the terrestri­ sult of a tradition of maintaining the number of al microfauna and comprises at least 100 times dinosaurian orders at two and archosaurian or­ as many species as the classes Aves, Mam­ ders at five in spite of a real diversity reflected malia, and Osteichthyes combined, is classified in an ever-widening fossil record. into a mere 28 orders (listed in OToole, ed., Two methodologies are at work in Linnaean 1986 but excluding extinct orders and certain zoological taxonomy. Taxa at or below the fami­ orders of uniramians once classified as insects). ly-group level are based primarily on species, Dinosaurs were ubiquitous throughout the descriptions of which require considerable de­ Mesozoic, comprising almost literally the entire tail. Genera and families are constructed by continental megafauna from the Early Jurassic grouping species together. This "bottom-up" to the Late Cretaceous. Among terrestrial tetra- methodology is reflected in the naming process pods, only the Cenozoic mammals have of the lower taxa, which is regulated by the achieved comparable dominance. Thus it is pe­ ICZN: A species, when named, must be grouped into a genus, whose name becomes

Parainfraclass Archosauria Cope, 1869 19 Taxonomic Considerations the first part of the species' binomial, and a Let me place the Bauplan idea in a dinosau- family must be named after an included genus. rian perspective. When dinosaurologists assem­ Hundreds of new genera and species, and ble to discuss their latest discoveries, they rare­ dozens of new families, of axe created ly speak of saurischians and ornithischians. In­ each year, primarily for extinct forms and stead, they focus on sauropods, theropods, an- small, cryptic extant forms. kylosaurs, stegosaurs, and so forth. Like the Contrasting with this is the "top-down" terms amniote and reptile, the terms saurischi- methodology governing taxonomy at the higher an and ornithischian are too general and com­ levels. Kingdoms, phyla, and classes are almost prise too many distinct morphological types to always based on general descriptions emphasiz­ open a dinosaur discussion satisfactorily. This ing common characteristics of wide groups of is a powerful clue to what hierarchic level, if organisms. The detail required to distinguish a any, the taxa Saurischia and Ornithischia species or genus is neither necessary nor de­ should be assigned. It is the categories of inter­ sirable to define a phylum or a class. The dis­ est to dinosaurologists that should lie at the or­ covery or definition of a new class or phylum is dinal level, not at the subordinal level where an infrequent and usually significant biological they have been classified for so long. event; supraordinal Linnaean taxa exhibit con­ In the classification used here, I have raised siderable stability. many archosaurian suborders to full orders for Caught in between these two methodologies the intuitive reasons articulated above. Each are the ordinal-level taxa. Precisely at this level order thus comprises a single Bauplan. The aet- does the "top-down" methodology collide with osaurs were quadrupedal, heavily armored her­ the "bottom-up" methodology, which implies bivores; the pseudosuchians were mainly lightly that defining and naming ordinal-level taxa armored quadrupedal ; the rhampho- should be a blend of both methodologies. I sug­ rhynchoids were mainly long-tailed pterosaurs; gest that the requisite compromise between the the brontosaurs were quadrupedal methodologies is to regard each ordinal-level with elongated necks and tails; the theropods taxon as containing a single morphological type were bipedal predators; the ornithopods were or Bauplan (Levinton, et aL, 1986) within its mainly bipedal herbivores; and so forth. It class. This intuitive notion is best characterized should be pointed out that many of the archo­ by example. saurian suborders were originally proposed as If extant mammals were classified according orders, and that suggestions to return some of to the traditional methodology used for the ar- them to the ordinal level appear occasionally chosaurs, there would be only six orders in­ even in the recent literature {e.g., Bakker & stead of 44: (1) a order for all mammals Galton, 1974). ancestral to the eutherians (corresponding Of course, each order must be defined by a roughly to the traditional "Thecodontia"); (2) suite of more detailed characters to ensure that an order for "primitive" eutherians, including it is not a polyphyletic assemblage of similar insectivores and primates (corresponding but unrelated forms (such as and an- roughly to the traditional Crocodylia); (3) an kylosaurs, which were both armored quadrupe­ order for bats (corresponding to the Pterosau- dal herbivores). As cladists will agree, it is ria, of course); (4) an order for carnivores (cor­ shared descent from a common ancestor —mo- responding to the Saurischia); (5) an order for nophyly where possible, elsewhere — all ungulates, sirenians, and cetaceans (corres­ that removes some of the arbitrariness and arti­ ponding roughly to the Ornithischia); and (6) ficiality from supraspecific taxa. Discussions of an order for rodents and lagomorphs. We can the archosaurian groups along these lines are see that such an arrangement for mammals is the substance of the remaining sections of this unsatisfactory. Why then continue to apply it to work. the archosaurs?

Taxonomic Considerations 20 Mesozoic Meanderings #2 other does not (D. Chure and J. S. Mcintosh, NEW SUBFAMIL1AL TAXA pers. comm.; R. E. Molnar, pers. coram.). It re­ mains unclear which was published first, al­ Protognathus Renamed though the latter is probably a preprint of the The monograph on Shunosaums Hi by former. In either case, Kim's did ap­ Zhang (1988) introduced a new sauropod gen­ pear in print, in a properly distributed docu­ us and species, Protognathus axyodon Zhang, ment, as a with a designated type 1988, whose type specimen is a dentary from species and type specimen, some two years be­ the Lower Shaximiao Formation of Dashanpu, fore Jensen's. Kim had misidentified the most Zigong (Institute for Vertebrate Paleontology diagnostic part of the type specimen, a partial and Paleoanthropology CV00732). , as an ulna (Paul, 1988a), which led The generic name Protognathus is preoccu­ him to imagine his sauropod was larger than it pied by Protognathus Basilewsky, 1950, a genus really was. Furthermore, the nature of the re­ of central African carabid beetles. The name maining type and referred material makes Protognathus also appears misspelled as Porto- Kim's name Ultrasaurus a nomen dubium. But gnathus [sic] in the English abstract to Zhang's Jensen's name is still preoccupied by Kim's, so paper, but this is a typographical error and can­ I propose the name Ultrasauros n. gen. to re­ not be considered a properly proposed replace­ place it. ment name for Protognathus. Therefore, I pro­ pose the name Protognathosaurus n. gen. to ac­ The ICZN recommends that a new genus- commodate Zhang's species Protognathus axyo­ group name differ from similar names by more don. This makes the renamed type species Pro­ than just its termination or small differences in tognathosaurus axyodon (Zhang, 1988). spelling (ICZN, 1985: Appendix D, section I, paragraph 3), but in the same work the ICZN Ultrasaurus Renamed regards generic names that differ by a single let­ One of the most famous recently named sau­ ter as distinct (Article 56[b]). Inasmuch as it is ropod genera is Ultrasaurus, whose name ap­ unlikely that Kim's genus will receive wide at­ peared in print as early as 1979 as a nomen nu­ tention, and in view of the longstanding and dum in popular dinosaur publications. James continuing interest in Jensen's genus, I think A. Jensen applied the name to the scattered re­ that as much of Jensen's generic name should mains of an enormous sauropod that he dis­ be retained as possible. It is unlikely that much covered in the Dry Mesa Quarry in Colorado. confusion between the two genera will result, He chose the name "Ultrasaurus" to signify so the single-letter name change (suggested by that the dinosaur was even larger than the sau­ Jensen, pers. comm.) to Ultrasauros is justifia­ ropod "," which he had unearthed ble. in the same quarry in 1972 and whose name at J. S. Mcintosh (pers. comm.) informs me the time was also still a nomen nudum. Jensen's that the type specimen of Ultrasauros macin- "Supersaurus" and "Ultrasaurus" remained toshi is a dorsal , Brigham Young Uni­ nomina nuda until 1985, when formal descrip­ versity 4044, whose specimen number was list­ tions of the genera were published (Jensen, ed incorrectly as BYU 5000 in Jensen, 1985. 1985). In the meantime, however, Korean pale­ ontologist Haang Mook Kim had applied the Singular Genitives Corrected name "Ultrasaurus" to fragmentary sauropod Four dinosaur species have been named in material from Korea, believing that this also the past two decades in honor of families rath­ represented a sauropod larger than "Supersau­ er than individuals: tilletti Os- rus." Kim's "Ultrasaurus" remained a nomen trom, 1970; edwardsi Ostrom, 1970; nudum until 1983, when Kim formally de­ Avaceratops lammersi Dodson, 1986; and Steno- scribed the genus and its type species, Ultrasau­ tholus kohleri Giffin, Gabriel & Johnson, 1988. rus tabriensis. I have seen two versions of Kim's The ICZN (1985: Article 31[a][ii]) states that a 1983 paper, virtually identical except that one specific name in honor of more than one per­ names the type species U. tabriensis and the son must take the genitive plural ending -orum

Parainfraclass Archosauria Cope, 1869 21 Taxonomic Considerations or -arum; the former ending is to be used when was referable to the species Megalosaurus dun­ there is at least one male among those honored. keri. This, however, is now impossible. Tenontosaurus tilletti Ostrom, 1970 was In two forthcoming papers (Olshevsky, in named after the Lloyd Tillett family of LovelL preparation a, b), I have disentangled the sur­ Wyoming, and Sauropelta edwardsi Ostrom, feit of confusion that has arisen concerning the 1970 was named after Nell and Tom Edwards names , Megalosaurus dunkeri, and of Bridger, . Avaceratops lammersi Megalosaurus oweni since tliey were coined. Dodson, 1986 honors at least eight members of Most of the confusion stems from misidentified the Lammers family of Shawmut, Montana. type and referred specimens, and some stems Stenotholus kohleri honors Terry and Mary from outright errors in figures and figure cap­ Kohler of Milwaukee, Wisconsin (Giffin et al., tions that have propagated through the litera­ 1987). Stenotholus kohleri was subsequendy ture in uncritical reviews. Before I can publish found to be a junior synonym of Stygimoloch these results, however, I must travel to London spinifer (Gabriel & Berghaus, 1988), but it nev­ to examine the specimens in person, to photo­ ertheless remains necessary to spell the specif­ graph and measure them for comparative ic name correctly. In each case, the genitive sin­ study. Based on photographs kindly supplied gular ending -i is inappropriate and constitutes by Stephen Pickering, Eric Buffetaut, and Jean an incorrect original spelling of the specific Le Loeuff, however, I am already convinced name, as described in Article 32(c) of ICZN, that R1828 and R2559 cannot possibly belong 1985. Since at least one male is present among to the genus Megalosaurus and represent two die honorees of each of the specific names, the new genera of Wealden theropods. ICZN mandates that the names be respelled as The tooth species Megalosaurus dunkeri, follows: through one of those unfortunate mishaps al­ Tenontosaurus tillettorum Ostrom, 1970 luded to above, can no longer be separated Sauropelta edwardsorum Ostrom, 1970 from the genus Altispinax; it was made its lec- Avaceratops lammersorum Dodson, 1986 totype species by Kuhn (1939). The type tooth Stenotholus kohlerorum Giffin, Gabriel & (for which I still have no specimen number, Johnson, 1987 and which may, according to Stephen Picker­ ing, have been lost from the University of Mar­ Becklespinax n. gen. burg collection) is unusual in having no serra­ Huene (1923) coined the genus Altispinax tions on die mesial carina. Dames regarded for two species of Megalosaurus from die Weal- this as significant enough to erect a new spe­ den of Great Britain. The older species, Megal­ cies of Megalosaurus, but Lydekker considered osaurus dunkeri, had originally been estab­ this simply the result of wear. Then Lydekker lished by Dames (1884) for a single unusual took that unwarranted step of referring almost carnosaurian tooth from Hanover, Germany. all the Wealden theropod ma­ The other species, Megalosaurus oweni, had terial to Dames's species, instead of isolating been established by Lydekker (1889a) for a par­ the species and perhaps creating new taxa of tial left metatarsus (British Museum [Natural his own. History] R2559) originally described by Owen (1857) as belonging to the nodosaurid Hylaeo- In particular, Lydekker referred the three saurus. Huene based his name on an articulat­ vertebrae, BMNH R1828, to Megalosaurus dun­ ed series of three dorsal vertebrae (British Mu­ keri. This specimen was discovered by noted seum [Natural History] R1828) with gready amateur fossil collector Samuel H. Beckles, elongate neural spines that Lydekker (1888b) Esq., in the Lower Wealden of East Sussex had catalogued, along with almost all other sometime in the early 1850s. Owen (1855: T. Wealden theropod material, in the species Me­ XIX) figured the vertebrae at life size, and in a galosaurus dunkeri. Altispinax was created as a subsequent work (1856, oddly not the work in conditional name, without a type species, in which the specimen was figured) described case it could someday be shown that R1828 them as anterior dorsal vertebrae of Megalosau­ rus. There is little question that Owen already

Taxonomic Considerations 22 Mesozoic Meanderings #2 had the specimen in hand when he supervised eni, die theropod metatarsus (BMNH R2559) the construction of the dinosaur models for the that Owen had originally referred to Hylaeosau- Crystal Palace. The "humpbacked" appearance rus (with die incorrect number R2556). Hulke of the Crystal Palace Megalosaums is certainly (1881) had earlier noted the theropod nature based on R1828's elongate neural spines. of the metatarsus, but he did not refer it to any To go into all the nomenclatural problems known genus, because his paper was concerned that those specimens inspired is beyond the widi armored dinosaurs. Unfortunately, Lydek­ scope of this work. In the case of R1828, it is ker seems to have been misled by Owen's sufficient to note that the vertebrae are poster­ (1857) figure of the metatarsus (which pre­ ior dorsals, probably #8-10, and that except sented a mirror image of the actual specimen): for the very tall neural spines, they most closely He misdescribed the left metatarsus as a right, match dorsals #8-10 of the Argentine genus and shortly thereafter (Lydekker, 1890a) re­ Piatnitzkysaums (Bonaparte, 1986a) in the con­ ferred two more metatarsals (BMNH R604d formation of the apophyses and laminae and in and R1525) to Megalosaums dunkeri, because the position of the neural spine atop the neural to him they were similar to —but not identical arch. The firm contact between the apexes of with—the metatarsals of Megalosaums oweni. the neural spines of vertebrae #9 and 10 (and, Although they had been found about 180 yards presumably, later vertebrae in the series) is a apart in die Hollington Quarry, Lydekker con­ diagnostic feature of the specimen that occurs sidered diem as belonging to the same individu­ in no other known theropod genus. It is possi­ al It was not long thereafter that Lydekker ble that the neural spine of vertebra #8 is not (1890b) removed the British Museum Wealden broken off at the top but is naturally shorter theropod specimens from Megalosaums dunkeri than die spine of #9. This would constitute and referred them to his own species. another very strong diagnostic feature of the Huene, in a series of papers on saurischians genus, but it requires physical examination of (1926a, 1926b, 1932), misrepresented the type the specimen before it can be confirmed. The specimen of Megalosaums oweni as four meta­ neural spines and die vertebrae are very dif­ tarsals. This error remained uncorrected in sub­ ferent from those of and sequent literature, surfacing in Steel, 1970 and . Relative to the lengths of die even as recently as Molnar, 1990, both of which centra, the neural spines of R1828 are the tall­ considered the two referred metatarsals est known in die Theropoda except for Spino­ (R604d and R1525) as cotype specimens of Me­ saurus aegyptiacus. I can find little justification galosaums oweni and overlooked the real type for referring R1828 to die genus Acrocanthosau­ specimen, R2559. rus and making it the type specimen of the spe­ I haven't the space here to provide all the cies Acrocanthosaurus altispinax (Paul, 1988b). details of these misidentifications, and I refer In view of die resemblance of R1828 to figured the reader to the second of my forthcoming pa­ vertebrae of die eustreptospondylid Piatnitzky- pers on this subject (Olshevsky, in preparation saurus, I have removed die species Acrocantho­ b) for a more complete study. Suffice it to say saurus altispinax from die allosaurid genus Ac­ diat the type metatarsus of Megalosaums oweni rocanthosaurus into a new eustreptospondylid is more slenderly built and has a proportionate­ genus, which I name Becklespinax, in honor of ly larger and more robust metatarsal III than a Samuel H. Beckles, die discoverer of die type metatarsus referred to Megalosaums bucklandii specimen. The type species of die genus dius (Molnar, Kurzanov & Dong, 1990: Figure becomes Becklespinax altispinax (Paul, 1988). 6.29K). The species Megalosaums oweni is therefore removed from die genus Megalosau­ Valdoraptor n. gen. ms and is made the type species of the new gen­ Having referred most of die Wealden thero­ us Valdoraptor ("Wealden robber"). The type pod genera to Megalosaums dunkeri (Lydekker, metatarsus, R2559, shows no signs of having a 1888b), Lydekker subsequently (1889a) re- proximally pinched metatarsal III, so I tentative­ described, as a new species, Megalosaums ow­ ly refer the genus to the Allosauridae, pending

Parainfraclass Archosauria Cope, 1869 23 Taxonomic Considerations completion of my forthcoming paper. The prox­ Troodon bakkeri, new combinations for Pectino- imal ends of the metatarsals are worn away, so don asiamericanus and Pectinodon bakkeri. it is difficult to ascertain their configuration In Theropodomorpha (Theropoda incertae from the illustrative material available to me. sedis): Orthogoniosaurus rawesi, new combina­ The type species of the genus becomes Valdo- tion for rawesi. raptor oweni (Lydekker, 1889). In Sauropodomorpha (Brontosauria; Anchi- sauridae): sinensis, new combina­ Other New Combinations in the Table tion for sinensis. In Pterosauria (Pterodactyloidia; Pterano- In Sauropodomorpha (Brontosauria; Brachi- dontidae): Geostembergia stembergi and Geo­ osauridae): brancai, new combina­ stembergia walkeri, new combinations for Pter- tion for (Giraffatitan) brancai. anodon (Geostembergia) stembergi and Pteran- In Ornithischia (Ankylosauria; Nodosauri- odon (Geostembergia) walkeri. dae): Chasstembergia rugosidens, new combina­ In Theropodomorpha (Theropoda; Tyranno- tion for (Chasstembergia) rugosi­ sauridae): Tarbosaums turpanensis, Tarbosau- dens. nis luanchuanensis, and Tarbosaums lanpingen- In Ornithischia (Ornithopoda; Hadrosauri- sis, new combinations for turpan­ dae): Anatotitan longiceps, new combination ensis, Tyrannosaurus luanchuanensis, and Tyran­ for Trachodon longiceps. nosaurus lanpingensis. For explanations, see the notes for the in­ In Theropodomorpha (Theropoda; Troo- dividual taxa in the table. dontidae): Sauromithoides asiamericanus and

Taxonomic Considerations 24 Mesozoic Meanderings #2 Archosaur Phylogeny

HE ARCHOSAURS were once the most im­ General Considerations Tportant group of terrestrial vertebrates. Among terrestrial vertebrates, evolution usu­ They dominated the Jurassic and Cretaceous ally follows Cope's Rule (Stanley, 1973). That faunas the way mammals have dominated Ceno- is, larger, more specialized forms evolve from zoic faunas, which is one of the reasons they smaller, generalized forms. I will avoid the are so fascinating to study. Amojig_lhe_^rcho- question of what the terms "generalized" and ^aurs are numbered the largest terrestrial pred­ "specialized" mean; but the pattern of size in­ ators, the IargesF flying creatures, and the larg­ crease has a simple and cogent explanation. All est Tand animals of aU time. After the Creta­ other things being equal, larger individuals ceous-Tertiary extinction event, the archosaurs tend to dominate their smaller contemporaries, were badly decimated; only 22 species in 8 gen­ outcompeting them for resources and leaving a era (Ross & Garnett, eds., 1989) — all crocodili- disproportionate number of offspring. This se­ anst most endangered—remain extant. But if lection effect induces the general evolutionary the cladistic viewpoint of the archosaurs is tak­ trend toward size increase noticeable in the ver­ en, then we must add 9672 extant bird species tebrate fossil record. Counteracting this trend to the count (as tabulated in Sibley & Monroe, may be such adverse circumstances as heavy 1990). predation, wherein larger individuals simply be­ Like the fossil records of most groups, the come bigger targets less able to find conceal­ archosaur fossil record is generally awful. This ment; and scarcity of resources, when larger in­ is partly because most of the archosaurs were dividuals are less able to locate sustenance. t'errestrial-ardimals that lived in nondepositfonal The latter circumstance gives rise to island-en­ environments, and partly because most of the demic dwarfism, for example. Also counteract­ evoluriofiarycfagnges among tne archosaurs oc­ ing this trend are requirements of physiological curred ln~"tne small tonns, which required ex- fitness: giant individuals are seldom as fit as cgpflonal conditions tor preservation_as--foss2b. normal-size individuals. There is a limit to how Consequently, there are many gaps in our knowledge of their evolution. Some may say Bauplan of a particular species" before thlTspe- that it is through these gaps that I am driving cies itself musfchange. Finally, small verte­ the large truck of my phylogeny, but I think brates tend lo attain sexual maturity faster and that we can still say something about what hap­ have larger litters than large vertebrates. This pened in those gaps. Like the "dark matter" of results in a faster genetic turnover among the the universe, which makes its presence known smaller forms (Simpson's "tachytelic" evolu­ solely by its gravitational effects, the as-yet-un­ tion), which in the absence of predation can known archosaurs that have fallen through the radiate rapidly into many lineages. As larger cracks in the fossil record have sometimes left forms evolve, their evolutionary tempo slows their evolutionary traces on the forms we have (Simpson's "bradytelic""evolution), and the ten­ already discovered. dency to evolve wholly" new HWxptStie greatly decreases. These effects are quite evident in the evolution of the archosaurs.

Parainfraclass Archosauria Cope, 1869 25 Archosaur Phylogeny The antorbital fenestra seems to have ap­ DEFINING ARCHOSAURS peared abruptly in the Diapsida toward the Defining the archosaurs as a reptilian sub­ end of the . The earliest-known archo­ group has proved difficult. As__discussed_by saurs possessed large fenestrae; only one diap­ Benton^jStJClark-aggg) and Benton (1990a), sid taxon is known with what can be consid­ onejaroj30sal_is_ to make theArchosauria the ered an "incipient" antorbital fenestra. But smallest clade containing both the extant since the earliest archosaurs were undoubtedly CfScodySa and A^sTlKe~jCTOwn group""aetihi- spiajL Ug£tJy_jbujICa^ tion^ A_second proposans"T5 choose" a~ggfticn- preserved as fossils, I take the position that the lar suite of characters that sets the archosaurs abrupt appearance of the Antorbital tenestrais apan within the Diapsida, ensuring tnat the an illusion resulting from the lack of a fossil charterers chosen are sufficient to include "both record. In view of the absence of forms inter­ Crocoayuarand Aves. Despite being cladistic, mediate between the archosaurs and the other both proposals clearly partake of a certain arbi­ diapsid reptiles, the antorbital fenestra, what­ trariness, and there is no satisfactory way to ever its origin, remains the primary part of the consider either method of defining the ar­ convenient but somewhat slender morphologi­ chosaurs—that is, choosing which node to call cal and fossil-record gap that defines the Ar­ Archosauria on the diapsid cladogram —more chosauria. "natural" than the other. There is, on the other hand, a truly enor­ V It is necessary to point out that two different mous morphological and perhaps also physio­ jp'oups are called Archosauria in the current lit­ logical gap between the known archosaurs and erature: the clade Archosauria and the traditio­ their paramount descendant group, the class nal reptilian subgroup Archosauria, which is Aves. Chatterjee (1991: 317) lists 23 cranial not a clade but a parataxon, because it does apomorphies possessed by his new species Pro- notjnclude the birds. There is certainly~a need toavis texensis in common with Aves that are for a name for thaTgroup of animals that are "not found in any archosaurs," even though its archosaurs but not birds —probably more so postcranial anatomy differs little from what than for the archosaurs plus the birds—but might be expected in an arboreal small thero- strict cladistics does not supply it. Having the pod. Later birds, with the modifications to same name for two different groups is aestheti­ their postcranial anatomy that evolved as adap­ cally unacceptable, but since my nomenclature tations to powered flight, are much further re­ is not strictly cladistic, I refrain from coining a moved from the theropod Bauplan. Those mor­ new name for the clade Archosauria. I have phological differences necessitate subtracting elected to use the name Archosauria for the the clade Aves from the clade Archosauria and traditional parataxon, and I will simply rely on defining the Archosauria as a diapsid parainfra- context when it is necessary to distinguish be­ class. Aves may then be retained as a tradition­ tween the two different "Archosaurias." al (and monophyletic) class. The archosaurs diversified to such an extent But just what constitutes the class Aves? that there is no synapomorphy uniting all of For over a hundred years, it was simplest to de­ them. Nevertheless, I follow Charig (1976a) fine the Aves by the (in most cases presumed) and Benton (1990a) in considering the k^yar- presence of feathers, a strong synapomorphy rJiosanriqp synapomorphy the presence of an uniting with later birds. The total antorbital fenestra; Benton lists seven addition­ absence of well-documented feathered interme­ al synapomorphies. The antorbital fenestra be- diates between Archaeopteryx and its theropod came closed in later crocodilians and ornithis- forebears helped to provide a very sharp line chians, and it merged with the narial opening of demarcation between Aves and Reptilia. in later pterosaurs, but loss of the fenestra is It is recognized, however, that feathers them­ not a radical enough reversal to warrant exclud­ selves evolved from reptilian scales, their ear­ ing those groups from the Archosauria. lier homologues. The featherlike structures ob­ served in (Sharov, 1970) presum-

Archosaur Phytogeny 26 Mesozoic Meanderings #2 ably represent or are derived from a stage in birds in which the forelimb elements had entire­ that evolutionary history. Are they then to be ly lost their grasping function by fusing into a counted as feathers, supporting reference of "true" wing. There is little chance that a flight­ Longisquama to the class Aves? Or are they to less form with grasping forelimbs—which we be considered scales, supporting reference of would naturally call a theropod dinosaur— Longisquama to the paraclass Reptilia? The would have evolved at or above this stage of fossil record of Mesozoic birds may be awful, avian evolution. In birds descended from fully but the fossil record of feathers is truly abys­ volant ancestors, the wings are usually reduced mal. I suggest, in view of their rarity in the fos­ or vestigial and seldom even reacquire clawed sil record and the morphological evolution they hands (though ostriches have them). must have undergone in the early history of the Two avian clades originate near this point in archosaurs, that the presence of feathers not be the avian cladogram. Cracraft (1988) calls the used to define the class Aves. This is why I re­ more inclusive clade (Haeckel, gard feathers as a plesiomorphic character re­ 1886), the other Carinatae (Merrem, 1813); he tained by birds from ancestral theropods. does not employ Carinatae in its original sense, As long as Archaeopteryx was comfortably namely, apposed to Ratitae Merrem, 1813. The ensconced as the "oldest bird," there was no only ornithuran birds Cracraft regards as not compelling reason to exclude it from the class carinate are the hesperornithiforms (other au­ Aves, and no compelling reason to discard thorities, e.g., Gauthier, 1986a, 1986b, and Chat­ feathers as an avian synapomorphy. But the dis­ terjee, 1991, include more). These were Creta­ coveries of fully volant (although not yet unde- ceous toothed diving birds with vestigial wings scribed) birds from the of that I think perfectly exemplify flightless birds (P. C. Sereno, pers. comm.; Dong Z., descended from fully volant, that is, carinate pers. comm.), from the Late Triassic rather than merely ornithuran (sensu Cracraft), of (Chatterjee, 1991), and Iberomesomis ancestors. Tomerali from the Early Cretaceous of Spain Cracraft lists many characters that define (Sanz, 1990), among others, have made it neces­ carinate birds, including a typically avian pec­ sary to take a harder look at conventional avian toral girdle with enlarged or keeled sternum phylogeny. It has begun to seem more and and elongate coracoids. He also lists many or­ more as if Archaeopteryx was a "living fossil" in nithuran characters, such as a greatly reduced the : a small, feathered, habitually tail and a strongly opisthopubic , in which volant theropod dinosaur that probably coexist­ the ilia extend caudally to include numerous ed with more advanced birdlike forms better sacral vertebrae and the pubes extend caudally capable of powered flight. parallel to the ischia (usually fusing with them In the archosaur phylogeny I have construct­ and the ilia). Evidence from new discoveries ed, I imagine the commonly accepted theropod shows (Sanz, 1989; Chiappe, 1990: Figure 38), dinosaur groups as originating from various however, that the carinate wing and pectoral kinds of feathered gliding and flying forms. girdle appeared prior to the ornithuran pelvis. While this hypothesis seems to me to answer This would make the clade Ornithurae a sub- many questions about theropod and avian ori­ clade of the Carinatae {contra Cracraft). The gins, it does complicate theropod-avian taxono­ tail of a flying animal like Archaeopteryx helped my. Do we classify the theropods as birds, or to stabilize it in flight, so that it did not need to do we classify those aerial theropods as dino­ rely on the volant ability of its wings alone to saurs (or "dino-birds")? I have opted for the keep it aloft. Once birds were able to fly mainly latter choice, because the skeletal anatomy, par­ or solely with their wings, that is, became un­ ticularly the postcranial anatomy, of those stable powered fliers, their tails were free to "dino-birds" was evidently much more like that shorten and to become modified into the acces­ of what we traditionally call small theropods sory flight appendages that they are in extant than that of volant birds. The class Aves, to me, birds. Functionally, therefore, it makes more begins not with Archaeopteryx but with those

Parairtfraclass Archosauria Cope, 1869 27 Archosaur Phylogeny sense for the carinate clade to include the or- Potentially the most interesting feature of J nithuran clade rather than vice versa. the skull of Mesenosaurus is the small size of To summarize, the parainfraclass Archosau- the temporal fenestra. Ivakhnenko & Kurzanov ria is here defined to include all diapsid rep­ take this as evidence that archosaurs evolved rtiles possessing antorbital fenestrae, together the diapsid condition independently of the oth­ with all their descendants except the carinate er diapsid reptiles. In view of the rather large birds, which are regarded as a separate class, number of characters shared between archo- * -_Aves. This definition approximates the current saurs and other diapsids (Benton & Clark, usage of the term Archosauria among noncla- 1988), however, this conclusion may be prema­ distic taxonomists (e.g., Charig, 1976a), and if ture. , the class Aves is not excluded, the resulting Being an Early Permian reptile, Mesenosau-i <* clade coincides with Archosauria as defined by rus is temporally well placed to be a basal ar-j Benton (1990a). This clade Archosauria in­ chosaur. The earliest undoubted archosaur, cludes the entire "crown-group" clade Archo­ however, is the Late Permian proterosuchid^4r- (Benton & Clark, 1988), as well as a few chosaurus rossicus, recently redescribed by Sen- primitive thecodontian groups that would other­ nikov (1988). It, and all later proterosuchids, wise be consigned to a cladistic limbo as serial were specialized archosaurs clearly part of a archosaur outgroups (or to a more inclusive lineage that originated before the Late Per­ clade ). mian (Charig, 1976b). With the exception of Mesenosaurus, the fossil record of that lineage is entirely nonexistent. EARLY ARCHOSAURS The proterosuchids were archosaurs special- \ ized for a riparian lifestyle. This is curious, be- / Efremov (1940) described Mesenosaurus ro- cause most of the later archosaurs were highly meri, from the Early Permian of Russia, as a adapted to terrestrial or aerial lifestyles. Only a pelycosaur but later (1955) referred to it as a few, such as the parasuchians, hupehsuchians, primitive archosaur. Ivakhnenko & Kurzanov and crocodilians, remained (or became) semia- (1978) redescribed the type skull and noted a quatic or fully aquatic. Throughout this paper, number of archosaurian characters, including a I assert that the fossil_record is strongly bi- minute antorbital fenestra. A photograph of as&d^Jtsiperbiased— againsLihe__preservation of )4- the entire skeleton appears in Ivakhnenko & small, fully terrestrial vertebrates in favor of ri­ Korabelnikov (1987: 183), who identify it as a parian and aquatic forms. This is~whythe pro- primitive archosaur. Unfortunately, the illustra­ terosucEds"^njoY"lTTnio3est worldwide fossil tion is too indistinct to make out anatomical de­ record while the record of the other Permian tails, but the limb proportions and general mor­ and Early Triassic terrestrial archosaurs does phology of the specimen do not contradict an not exist This is also why I will not accept a archosaur identification. Evans (1988), in a cla­ phylogeny in which the proterosuchids are con­ distic study of nonarchosaurian and problemat­ sidered ancestral archosaurs, despite the priori­ ic diapsids, concluded that Mesenosaurus was ty of their appearance. not an archosaur but an early diapsid offshoot. But in the absence of evidence to the contra­ She identified the small antorbital fenestra of ry (and in the absence of any fossil record at Ivakhnenko & Kurzanov as a lacrimal foramen. all), the proterosuchids may be considered a But Ivakhnenko & Kurzanov had already locat­ side branch within a larger parataxon, the Pro- ed the lacrimal duct at a different site on the terosuchia, that would include those hypotheti­ skull, so Evans's identification of the antorbital cal ancestral archosaurs, as in Charig, 1976a. fenestra as a lacrimal foramen is not certain. In particular, Mesenosaurus can provisionally For the purposes of this list, I have provisional­ be grouped therein. Along with the characteris­ ly accepted Ivakhnenko & Kurzanov's identifi­ tic antorbital fenestra, the proterosuchians re­ cation of Mesenosaurus as a very early archo­ tained many plesiomorphic diapsid characters, saur. such as the diapsid skull, palatal teeth, unfene-

Archosaur Phylogeny Mesozoic Meanderings #2 strated , "saurischian" pelves, primi­ fully, correlating it with the development of the tive mesotarsal ankles, a significant size dis­ -normal (CN) and ^crocodile-reyerse parity between fore and hind limbs, a sprawl­ (CR) tarsi in the semi-erect forms. Both can be ing, lizardlike posture, and a long tail. Most of derived straightforwardly from the primitive those characters became lost or heavily modi­ mesotarsal tarsi of the Proterosuchldae (Krebs, fied in later archosaurs, and the evolutionary 1963), as adaptations to keep the hind fc>ot,en- patterns of these modifications broadly define tiffljQin~die ground (instead ot at an angle) how the archosaurs are classified and how we while the hind limb was held in a semi-erect po­ understand their phylogeny. sition. Both_aj£_characterized by a large calcan- eum with a caudally directed tuber. In living crocodflesTirTeiia,6^~aTOEnesTo~ffie tuber that THECODONT1AN ORDERS allows the animal to raise itself off the ground while walking (Charig, 1972; Carroll, 1988: Over the more than thirteen decades since 279), and this was presumably the function of the Thecodontia was first recognized (Owen, the tuber in all the early archosaurs that had it. 1859), it has lost its original conception and has This adaptation undoubtedly abetted the signifi­ expanded to include an ever-increasing mor­ cant increase in body size and weight under­ phological range of archosaurian taxa. Among gone during the evolution of the "thecodon- these are the feathered glider Longisquama; tians" in the Triassic. the gliding reptile Sharovipteryx; various large, In the CN ankle, a peg from the astragalus heavily armored, quadrupedal herbivores; some inserts into a hollow in the calcaneum at the small, gracile, bipedal predators; a number of movable joint between the two tarsal elements. semiaquatic piscivores; and many medium-size In the CR ankle, the peg is reversed, going to gigantic quadrupedal carnivores. I find it from calcaneum to astragalus. The boundary astonishing that a single order was made to ac­ between the calcaneum and astragalus appears commodate reptiles with such divergent body to be evolutionarily labile, however, so the di­ plans while at the same time excluding the croc­ rection of the peg may not be as phyletically sig­ odiles. Merely comparing the wide Bauplan di­ nificant as the simple presence of the calcaneal versity encompassed within the traditional tuber. Indeed, the shapes of the astragalus and "Thecodontia" with the restricted Bauplan di­ calcaneum are complicated (Benton, 1990: Fig­ versity of extant vertebrate orders demon­ ure 13), and, as in a "yin-yang" symbol, it is strates how necessary it has become to redefine sometimes unclear which element had the peg the group. and which had the hollow. Originally, the name "Thecodontia" was In this work, the traditional order "Theco­ coined for reptiles whose teeth were individual­ dontia" is elevated to a parasuperorder and is ly socketed in their . The fact that some in turn partitioned into several orders. These reptiles later referred to the group had acro- orders are restricted primarily to archosaurs dont, subthecodont, or no teeth at all, and that thought to have possessed tarsi with calcaneal most reptiles with thecodont dentitions (such tubera. Most of these thecodontian orders had as most dinosaurs) were excluded from the been subsumed into the traditional "Thecodon­ "Thecodontia," does not invalidate the name tia" as suborders, though some had originally for taxonomic purposes. The complicated his­ been proposed as orders. Only one of these, tory of the taxon is well covered by Charig tht- afnn-tnpntinnfH Proterosuchia, is a paragr- \\ (1976b). der with descendant taxa outside the Thecodon-^ The major evolutionary trend among the ear­ tia, which prevents the Thecodontia from being ly archosaurs in general and the "thecodon- a clade. Not only can all the other thecodon­ tians" in particular was the development of the. X tian orders be derived from the Proterosuchia, semi-erect and fully erect stance from the_^ but as I explain in succeeding sections, I bel­ sprawling stance that characterizes the Protero- ieve the pterosaurs and dinosaurs to be inde­ sucSaTXhaTig ~(1972)"~documented this trend pendently derived from the Proterosuchia as

Parainfraclass Archosauria Cope, 1869 29 Archosaur Phylogeny well. Taxonomists who require monophyletic plesiomorphic among archosaurs, since it was groups in their classifications should either re­ described in the eosuchian Heleosaurus (Car­ move the Proterosuchia from the Thecodontia roll, 1976). as an outgroup or simply restrict it to one or Some Triassic archosaurs previously classi­ both of the two included families, neither of fied as "theccKiontian?TaTroTits!de the superor- which can plausibly be regarded as ancestral to dejFThec^ontiaas constituted here. These in­ any later archosaur groups. Restricting the Pro­ clude the archosaurs that possessed mesotarsal terosuchia this way would relegate the common tarsi advanced over the proterosuchian condi­ ancestor of the archosaurs to an as-yet-un­ tion, among which were the earliest pterosaurs known group of Permian diapsids instead of an and dinosaurs. As usual, such "protoptero- as-yet-unknown group of proterosuchians. saurs" and "protodinosaurs" are almost entire­ The parasuperorder Thecodontia must in- 1 ly—and frustratingly— lacking from the fossil elude the order Crocodylia, whose present-day record. So not only is there a distinct morpho­ representatives are actually the last surviving logical gap between the Thecodontia and the thecodontians. Thus constituted, die Thecodon­ four mesotarsal-ankled clades (Pterosauria, tia is nearly congruent to Gauthier's (1986a, Theropodomorpha plus Aves, Sauropodomor- 1986b) clade Pseudosuchia and Benton & pha, and Ornithischia), there is a convenient — Clark's (1988) clade Crocodylotarsi. Thecodon­ and profound—fossil-record gap as well. tia is an older name than Pseudosuchia, howev­ Paraorder Proterosuchia er, and (as noted in Benton & Clark, 1988 and in Charig & Milner, 1990) it would be far more Broom (1906) originally created the order appropriate than Pseudosuchia, or "false croco­ Proterosuchia for the single genus Proterosu- diles," for a group containing the true croco- chus, but this order was later incorporated into diles(!). I do retain the group Pseudosuchia as the "Thecodontia" as a suborder (cf. Charig & a thecodontian order, but in a sense closer to Sues, 1976). In view of the morphological and that in which it has customarily been used. functional distance between the proterosuchids Crocodylotarsi is an appropriate name for the and the other thecodontians, I consider it best clade comprising all die thecodontians except to reinstate Broom's order within the parasu­ the Proterosuchia, Ornithosuchia, and Hupeh- perorder Thecodontia. Isolated subordinal stat­ . -4. us for the Proterosuchia was strongly advocat­ ed by Bonaparte (1984), and I have translated Besides calcaneal tubera, another character'^ this into ordinal status here. In view of its an­ occurring in the latex-T-hecodontia is the_pr.es- cestral position with respect to all the later the­ ence of dermal scutes. In lighdy armored forms codontians, the pterosaurs, and the dinosaurs, (e.g., orHtFosucmans), these were restricted to I consider it a paraorder. The Proterosuchia is a double row running along and above the the only group available to accommodate the ;. spine (the primitive .condition), but the bodies small, generalized archosaurs from whicn'all of some later forms (aetosaurs) are almost thejotEers are descended. ~ completely encased in latitudinal rings of ar­ mor. In crocodilians, the dorsal scutes and As noted above, controversy surrounds the their associated musculature help to support status of Mesenosaums romeri. Rather than the body (Frey, 1988a, 1988b). This suggests a erect a separate order for this single species similar weight-bearing function in the other (which further research may indicate it re­ thecodontians, in addition to whatever protec­ quires), I have tentatively placed it and its mon- tive role the scutes had. Dermal armor is otypic family into the order Proterosuchia as presendy unknown in the Proterosuchidae and the most primitive known archosaur. The lack the Erythrosuchidae (Charig & Reig, 1970), of a downturned excludes Meseno­ but its prevalence in the remaining thecodon­ saums trom the froterosuchidae. OnTyTurtner tian groups suggests that it originated within a eximlB-rtfolHSfTilirilva^^ or the closely related but as-yet-undiscovered family. discovery of more specimens, can confirm this Parasagittal dermal armor might even be classification.

Archosaur Phytogeny 30 Mesozoic Meanderings #2 Other than Mesenosaurus, the oldest archo- Order Orniithosuchia saurs~Sn~the fossil record TaTT mainly into,the In the Early Triassic, a second evolutionary siSglenjSily ProterosucMdafi* Broadly similar lineage among the archosaurs becomes evident in their anatomy, extant worldwide (known in the fossil record, with the appearance of "the from Australia, China, South , and the SoTlrirAfTicaB fofm Euvarkena cape/«^rsa*re- Soviet Union) from the Late Permian through lated forms from the Soviet Union and China. the Early Triassic, proterosuchids are thought Many authors have considered to have been small to medium-size riparian pis- close to the ancestry of practically all the other civores (Charig & Sues, 1976). None of the archosaurs, including the pterosaurs and the known genera was directly ancestf^rToanylatV dinosaurs (as discussed in Benton, 1990a). CT^rcn^saurs7b^calisFTn^y^o^^^3T^^25, Gauthier (1986a), for example, declared Eupar­ downturned p7e~maxiUa, anaujUgMiorgky_2ot keria imdiagnosable independently from his found uTTnoire adva^ced*^irchosaurs (Carroll, clade Archosauria, which is as close as cladists 1988: 271) excj£gt_theprimitive erythrosuchid come to stating that one taxon is ancestral to ^Sf?^?..-. (Charig, 1976bT Ivaknnenkc>"*"""& another. Indeed, it is difficult to dispute a close Korabelnikov, 1987: Figure 237; it may ultimate­ connection between the euparkeriids and the ly prove necessary to classify in a non-thecodontian archosaurs. In the phylogeny monotypic family in the Proterosuchia because developed below, however, I maintain that the of this, as was done by Ochev, 1958). But pterosaurs and dinosaurs acquired their ad­ smaller, more terrestrial versions of the proter- vanced mesotarsal ankles directly from the oSUChids, ciassitiable m ai-yet-Unknown__but primitive mesotarsal ankles of proterosuchians, pTot

Parainfraclass Archosauria Cope, 1869 31 Archosaur Phylogeny with thecodontians than with pterosaurs and di­ Order Pseudosuchia nosaurs (see also Bakker, 1986). The group Pseudosuchia has had a long and To wit, Omithosuchus is frequently cited as colorful history since it was first named in Zit- an ancestral dinosaur and is invitingly depicted tel's enormous paleontological handbook (Zit- in a bipedal pose by Walker (1964). Walker tel, 1887-90)-too long and colorful to be de­ even considered it, quite specifically, to be an tailed here. It suffices to note that over time it ancestral carnosaur. The popular dinosaur liter­ had come to include practically all the theco­ ature abounds with discussions of the origin of dontians except the proterosuchids, parasuchi- dinosaurs among "bipedal thecodontians," with ans, and crocodilians, and as late as 1986 Gau­ Omithosuchus furnished as the model dinosau- thier (1986a, 1986b) rediagnosed it to include rian ancestor. But although Omithosuchus was the crocodilians as well. Most previous authors a fully erect reptile (the femoral head was me­ have included the ornithosuchians in the Pseu­ dially inturned and the acetabulum was mildly dosuchia, sometimes restricting the Pseudosu­ perforated in some ornithosuchids), there is lit­ chia to include only those forms. Various tle evidence besides the size disparity between authors also often grouped putative "ancestral fore and hind limbs to substantiate bipedality. I dinosaurs" and "ancestral birds" with these, so agree with Bakker (1986) and Paul (1988b) when such creatures (e.g., Longisquama, Lago- that the ornithosuchids were quadrupedal pred­ suchus) emerged from the fossil record, they ators better classified in the Thecodontia than were classifed as pseudosuchians, too. So was ancestral to the dinosaurs. that primitive proterosuchian, Mesenosaurus A fully erect stance is known to have (Ivakhnenko & Kurzanov, 1978)! Of all the the­ evolved more than once within the archosaurs codontian groups, this order is most in need of (e.g., among the rauisuchians and the dino­ redefinition. saurs), and the inturned femoral head and per­ Like the ornithosuchians, many pseudo­ forate acetabulum were the way this was suchians exhibit dental and cranial morpholo­ accomplished within the Ornithosuchia; the gies strikingly similar to those of carnosaurs, non-dinosaurian nature of this adaptation in which caused earlier workers to classify pseu­ the group is betrayed by the CR tarsi. dosuchian teeth and jaws as specimens of Trias­ Gauthier (1986a, 1986b) greatly expanded sic theropods. This error resulted largely from the scope of the Ornithosuchia by diagnosing it our inadequate knowledge of pseudosuchian as the clade containing all the archosaurs from anatomy, and it was compounded when the Euparkeria to birds, the complementary clade shed teeth of large pseudosuchian predators to his Pseudosuchia. Interestingly, he noted sev­ were discovered in association with the re­ eral ornithosuchian characters (listed, e.g., in mains of prosauropod prey: An entire genera­ Benton, 1990a) as paralleled in various theco- tion of paleontologists was thus misled into con­ dontian clades. I regard these, contrarily, as sidering prosauropods to be ancestral or primi­ still more evidence of a close relationship be­ tive theropods (see, e.g., references in Gallon, tween the Ornithosuchia and the other theco­ 1985). Most workers now believe that the simi­ dontians. larities between pseudosuchian and theropod Ornithosuchians enjoyed a worldwide distri­ teeth are entirely homoplasious. bution (their shed teeth are sometimes classi­ As constituted here, the Pseudosuchia is a fied as Triassic "carnosaur" teeth) as a minor monophyletic order including most of the fami­ thecodontian side branch that became extinct lies of carnivorous quadrupedal archosaurs along with most of the other thecodontians to­ classified as Pseudosuchia by Krebs (1976), to­ ward the end of the Triassic. In assembling the gether with some apparently bipedal archo­ Ornithosuchia, I mainly followed Krebs (1976); saurs (poposaurians) probably derived from the order sorely needs a systematic restudy, them. Regrettably, I have had to exclude the particularly to resolve its relationships with the aetosaurs, which were the original constituents other archosaurs in more detail. of Zittei's group, because they were herbivores. Pseudosuchians, aetosaurs, parasuchians, and

Archosaur Phytogeny 32 Mesozoic Meanderings #2 crocodilians (clade Crocodylotarsi of Benton & Also included in the Pseudosuchia are the Clark, 1988) all probably acquired their CN archaeosuchians, better known as the protero- tarsi from an as-yet-unknown proterosuchian champsians, a side branch of crocodiloid ripar­ common ancestor as part of a suite of forelimb ian predators from the Triassic of South Ameri­ and hindlimb adaptations associated with in­ ca. Bonaparte (1971a, 1982, 1984) collected the creased size and weight, semi-erect stance, and proterochampsids in their own subgroup of the more rapid terrestrial locomotion. Among the Erythrosuchia (but Archaeosuchia Sill, 1967 pseudosuchians, Bonaparte (1982, 1984) recog­ takes precedence over Proterochampsia Bona­ nized a close connection between the erythrosu- parte, 1971a as the name of this taxon). They chids and the rauisuchids, the latter being basi­ apparendy form a clade distinct from (but less cally swifter, more efficient versions of the for­ derived than) the erythrosuchian-rauisuchian- mer, when he segregated them in the suborder poposaurian clade, and they may eventually Erythrosuchia outside the Proterosuchia. As he even acquire their own thecodontian order. I showed, the locomotor improvements of the classify them provisionally as the most primitive semi-erect erythrosuchians culminated in the pseudosuchian suborder. fully erect stance of the rauisuchians, conver­ An unusual armored archosaur from the gent with but anatomically different from that Late Triassic of , kaltenbachi of the ornithosuchians and the dinosaurs (raui­ Weems, 1980, was placed in its own monotypic suchians possessed horizontally inclined ilia suborder, Doswelliina, of die "Thecodontia" by rather than vertical ilia). This apparendy al­ its describer, who considered resemblances be­ lowed the evolution of bipedal (but, unfortu­ tween Doswellia and the aetosaurs (see below) nately, not particularly well known) forms such as convergent. Bonaparte (1982) nevertheless as and Poposaunts, whose family, considered Doswellia an aberrant , Teratosauridae (c/. Galton, 1985), I have while Benton & Clark (1988) were able to find placed in a new suborder, Poposauria. It is not a synapomorphy with the proterochampsids— clear whether the poposaurians derived directly loss of the postfrontal. I have followed their from the rauisuchids or represent a parallel opinion in provisionally classifying the Doswelli- development from another, as-yet-undescribed idae as a separate archaeosuchian family. The rauisuchian family, but in either case they dif­ of Doswellia is not known. fered sufficiently from the quadrupedal rauisu­ The problematic genus Lotosaums Zhang, chians that a new suborder is justifiable. (In 1975 from the Late Triassic of China, which this context, it should be noted that newly de­ has not yet been completely described, seems scribed long-necked, gracile rauisuchids [Senni- to be a derived rauisuchian with edentulous kov, 1990] from Russia may be close to ances­ jaws and neural spines elongated into a ridge tral poposaurians.) Should research deny the or sail along the back. I have only seen photo­ bipedality of the poposaurians, however, dien graphs of a mounted specimen (Olshevsky, the suborder Poposauria would have to be re­ 1991) whose general stance and pose suggest jected in favor of installing the Teratosauridae either an erythrosuchian or a rauisuchian. I as a rauisuchian family. have provisionally lumped it and odier proble­ Essentially, then, the parasuborder Erythro­ matic Triassic "sailbacked" genera into the suchia includes quadrupedal pseudosuchians family Ctenosauriscidae of the parasuborder with a semi-erect stance, the parasuborder Rauisuchia. I know of no cladistic analysis of Rauisuchia includes quadrupedal pseudosuchi­ the thecodontians that attempts to classify ans with a fully erect stance, and the suborder these forms. Since Lotosaums lacked dentition, Poposauria includes fully erect, bipedal pseudo­ it is not quite clear whether it was carnivorous suchians. I regard the erythosuchians as ances­ or herbivorous; in the latter case, it and the tral to die rauisuchians, which in turn were an­ other ctenosauriscids might require their own cestral to the poposaurians; hence the paraphy- pseudosuchian suborder. ly of the first two suborders. Pseudosuchians were thus a rather diverse and important group of thecodontians. In as-

Parainfraclass Archosauria Cope, 1869 33 Archosaur Phytogeny sembling this order, I have mainly followed the Phytosauria, created by Camp (1930). "Parasu­ systematic work of Reig (1961), Charig & Reig chian" means "beside crocodile," a succinct de­ (1970), Sill (1967, 1974), Krebs (1976), Bona­ scription of the numerous anatomical conver­ parte (1982, 1984), Benton & Clark (1988), and gences of parasuchians with crocodilians, but Sennikov (1989, 1990) - insofar as they do not "" means "plant ," an allusion conflict with one another. to a supposed herbivorous diet. Anyone who has beheld parasuchian teeth knows they were Order Parasuchia not herbivores! For these reasons I prefer the The parasuchians, or , are a mon- name Parasuchia for this order. ophyletic group of Late Triassic thecodontians Recent work has gotten the formidable task of worldwide provenance (Hunt & Lucas, of disentangling parasuchian taxonomy well un­ 1991). They are universally considered to have derway. The present list organizes the parasu­ been large, riparian or lacustrine predators chians according to the systematic studies in that occupied an ecological niche later taken Gregory, 1962; Westphal, 1976; Ballew, 1989; over by the crocodilians, which convergently ac­ Hunt, 1989; and Hunt & Lucas, 1989 and 1991. quired many parasuchian anatomical charac­ ters {cf. Hunt, 1989). By comparison with most Order Aetosauria other archosaurian orders, the parasuchian fos­ The aetosaurs are usually grouped as a pseu- sil record is strikingly robust, including many dosuchian family within the traditional "Theco- hundreds of specimens ranging from isolated dontia," but I consider them sufficiently differ­ teeth to complete and skeletons, dozens ent from the pseudosuchians that they warrant of species, and about a score of genera, all clas­ a separate order. They were the only known sifiable in but a single family. Much individual thecodontians to adapt to a herbivorous diet. variation due to growth allometry and sexual (It is not clear which of the three major herbiv­ dimorphism is present, and specimens often ex­ orous archosaur clades—the aetosaurs, the or- hibit morphologies transitional between estab­ nithischians, or the sauropodomorphs—be­ lished species and genera. Their fossil record is came plant-eaters first. The earliest known so rich that they are routinely used as strati- aetosaurs are from the , however, some­ graphic markers in the Upper Triassic of the what earlier than the earliest known ornithischi- southwestern United States. All this has con­ an, , and the earliest prosauro- tributed to the proliferation of synonymies and pods [Hunt, 1991].) Their relationship with the renamings in systematic studies of the group. other thecodontians is difficult to establish, but The reason for this is quite clear: Parasuchi­ Benton & Clark (1988) include them in the ans were well adapted to life in a freshwater clade Pseudosuchia on the basis of a number aquatic environment, which coincidentally hap­ of minor synapomorphies. This means they pens to be an environment in which fossiliza- could be derived archaeosuchians (paralleling tion is very likely to occur. Virtually all of para­ Doswellia), erythrosuchians, rauisuchians, or suchian evolution took place just where its rec­ an autapomorphic group. ord had the best chance of being preserved. All known aetosaurs were quite similar to By contrast, ancestral parasuchians are ab­ one another morphologically and fall into a sin­ sent from the fossil record (which might lead gle family, Stagonolepididae (whose name one to suspect that they were upland forms takes precedence over Aetosauridae by a mere that did not live near rivers). Parasuchians two months). They all had thick-boned skulls were highly derived thecodontians whose inde­ with piglike snouts, peglike teeth, and antorbi- pendent evolutionary history extends back into tal fenestrae inset into deep fossae. The articu­ the Middle or even the Early Triassic. lation point of the lower was located some­ It is rather unfortunate that parasuchians what below the tooth row. Their dermal armor, are usually called "phytosaurs" in the litera­ their most prominent characteristic, was devel­ ture. The term Parasuchia was coined by Lyd- oped into latitudinal rows of slender, rectan­ ekker in 1885, preceding by 45 years the term gular plates that encased the animal dorsally

Archosaur Phytogeny 34 Mesozoic Meanderings #2

mMHH! and ventrally. Rows of lateral spines ran from niche for large, riparian predators that one the neck and shoulders to the tail in some group of crocodilians (protosuchians) occupied genera. The pattern of the armor is diagnostic it, essentially abandoning its cursorial adapta­ to the generic level (R. A. Long, pers. comm.). tions in favor of much greater size and weight, All the aetosaurs were plantigrade, semi-erect relatively shorter legs, and a semi-erect stance. quadrupeds with CN tarsi. Even so, crocodilians did not lose all their adaptations for speed; extant forms are still Order Crocodylia capable of galloping when necessary to capture The Crocodylia is a well-studied archosaur a meal (Ross & Garnett, eds., 1989: 49). The clade extant from the to the last of the small, swift forms, the hallopodans, present (SteeL 1973). I can think of no reason apparently became extinct at the end of the save tradition to account for why it has been Jurassic. maintained as an order separate from die the- codontians in most archosaurian classifications. In this table, the less-advanced crocodilians Benton & Clark (1988) restrict the term Croco­ are grouped primarily according to Steel dylia to tie "crown group," that is, the smallest (1973), as modified by the additional taxonomic clade containing all the living crocodilians. This work of Crush (1984) and Benton & Clark clade and related ones are grouped together (1988). The orders Trialestia and Sphenosuchia and nested in a series of larger clades that cul­ seem not to be ancestral to any later groups, minates in the most inclusive clade, the but I have listed the Protosuchia as a parasub- (Walker, 1970). But it is this order because it is probably ancestral to all the group, not the "crown group," that many au­ later (unlisted) crocodilian groups. It and its de­ thorities (e.g., Carroll, 1988; Sues, 1989; Buffe- scendant groups (including the "crown group" taut, 1989) consider to be the Crocodylia, and I Crocodylia) comprise the clade Crocodylifor- follow this usage here. The clades included by mes of Benton & Clark. Benton & Clark in the Crocodylomorpha may Order Hupehsuchia be accommodated as subtaxa and parataxa Nanchangosaums and Hupehsuchus, two within the Crocodylia, but I do not deal with genera of highly derived aquatic reptiles from the advanced groups here. Only those taxa with the Middle Triassic of China, had been de­ morphologies close enough to those of other scribed only briefly (Wang, 1959; Young & thecodontians to have been occasionally includ­ Dong, 1972) until a thorough redescription was ed with them in other taxonomies are listed. published by Carroll & Dong (1991). Young & Some of the earliest crocodilians (sphenosu- Dong erected a new suborder, Hupehsuchia, chians and possibly trialestians) show speciali­ for Hupehsuchus and tentatively classified the zations for quadrupedal running, including a Hupehsuchia as highly derived, aquatic archo- slender body, fully erect long legs, and elongat­ saurs. Hupehsuchus was later synonymized with ed proximal carpal elements. The elongate car- Nanchangosaums (Dong, 1979). pals in particular persist even in extant forms Carroll & Dong's work clearly established and are an excellent synapomorphy uniting all that the two genera were separate both mor­ the crocodilians. Crocodilians are morphologi­ phologically and temporally, and that the Hu­ cally conservative, never straying far from their pehsuchia was different enough from all other original Bauplan, and they are, of course, the reptiles to warrant raising the group to a full archetypal CN-ankled, parasagittal^ armored order. Detailed anatomical restudy, however, thecodontians. All these considerations assure failed to reveal anything more about the rela­ ordinal status for the group within the Theco- tionships of the Hupehsuchia than that the or­ dontia. der belonged somewhere in the parasubclass It is interesting that the Crocodylia probably Diapsida. They did not, however, find any char­ originated as a group of smalL swift, quadrupe­ acters that would preclude its placement within dal predators. It was only after the extinction of the Archosauria. I must add parenthetically the parasuchians opened up an ecological that Carroll & Dong's restudy made hash of my

Parainfraclass Archosauria Cope, 1869 35 Archosaur Phytogeny comments about Hupehsuchus in a recent book Hupehsuchus displays a primitive mesotarsal review (Olshevsky, 1991). ankle and pentadactyl manus and pes that Parasagittal dermal armor and a small, mod­ were highly modified into paddles. This indi­ ified antorbital fenestra present in Hupehsu­ cates that if the Hupehsuchia does belong in chus and Nanchangpsaurus suggest to me that the Thecodontia, it represents a separate line­ the Hupehsuchia may be placed very provisio­ age whose origin lies in yet another as-yet-un­ nally within the parasuperorder Thecodontia. known group of proterosuchians.

Archosaur Phylogeny 36 Mesozoic Meanderings #2 Parasuperorden Thecodontia Owen, 1859

Census (excluding Crocodylia): 6 orders, 15 families, 115 genera (29 doubtful), 171 species (58 doubtful)

Paraorden Proterosuchia Broom, 1906 Census: 2 families, 10 genera, 12 species A. indicus Huxley, 1865 (Type) Family: MESENOSAURIDAE = Chasmatosaurus indicus (Huxley, 1865) Romer, 1956 = Epicampodon indicus (Huxley, 1865) Lydekker, 1885 Census: 1 genus, 1 species = indicus (Huxley, 1865) Genus: Mesenosaums Efremov, 1940 Genus: Archosaurus Tatarinov, 1960 = Mesonosaums Ivakhnenko & Kurzanov, A. rossicus Tatarinov, 1960 (Type) 1979 [sic] M. romeri Efremov, 1940 (Type) Genus: Chasmatosaurus Haughton, 1924 = Champsosaurus Romer, 1971/Cope, 1877 [sic] Family: PROTEROSUCHIDAE C. vanhoepeni Haughton, 1924 (Type) = vanhoepeni (Haughton, von Huene, 1914 1924) = Chasmatosaurus van Hoepeni von Census: 8 genera, 10 species Huene, 1926 [sic] = Chasmatosauridae Haughton, 1924 = Chasmatosaurus alexanderi Hoffman, = Chasmatosaurinae Kuhn, 1966 1965 = Pelycosimiidae Abel, 1919 C yuani Young, 1936 = Proterosuchia Broom, 1906 C ultimus Young, 1964 vide von Huene, 1908 = Chasmatosaurus yuani Young, 1958 non = Proterosuchinae Tatarinov, 1961 Young, 1936 NOTE: This family was initially proposed by Genus: Elaphrosuchus Broom, 1946 (juvenile Broom (1906) as a monotypic suborder contain­ Chasmatosaurus?) ing only the genus Proterosuchus. Von Huene E. rubidgei Broom, 1946 (Type) (1908) treated it as a family, but the name was first given its proper familial spelling in von Genus: Fugusuchus Cheng, 1980 Huene, 1914. F. hejiapanensis Cheng, 1980 (Type) Genus: Ankistrodon Huxley, 1865 Genus: Kalisuchus Thulborn, 1979 = Ankistridon von Huene, 1942 [sic] K. rewanensis Thulborn, 1979 (Type) = Epicampodon Lydekker, 1885

Parainfraclass Archosauria Cope, 1869 37 Thecodontia Owen, 1859 Genus: Proterosuchus Broom, 1903 ( = Chas- Genus: [To be described from the Triassic of matosaums?) the Soviet Union; Sennikov, 1990] P.fergusi Broom, 1903 (Type) Genus: Tasmaniosaums Camp & Banks 1978 PROTEROSUCHIA incertae sedis = Tasmaniosaums Dziewa, 1980 [sic] = Tasmaniosaums Cosgriff, 1974 [nomen Census: 1 genus, 1 species nudum] = Tasmaniosaums Banks, Cosgriff & Genus: Exiusuchus Ochev, 1979 Kemp, 1978 [nomen nudum] E. tuberculoris Ochev, 1979 (Type) T. triassicus Camp & Banks, 1978 (Type) = Tasmaniosaums triassicus Cosgriff, 1974 Genus: Rysosteus Owen, 1841 [nomen nudum] [nomen nudum] = Ryzosteus L. B. Halstead & Nicoll, 1971 = Tasmaniosaums triassicus Banks, [sic] Cosgriff & Kemp 1978 [nomen nudum] No type species named

Orden Ornithosuchia Bonaparte, 1971 Census: 3 families, 14 genera (3 doubtful), 15 species (3 doubtful)

Parafamily: EUPARKERIIDAE Family: ERPETOSUCHIDAE von Huene, 1920 Watson, 1917

Census: 6 genera, 7 species Census: 2 genera, 2 species

= Euparkeriinae Sennikov, 1989 Genus: Newton, 1894 = Dorosuchinae Sennikov, 1989 = Erpethosuchus Bonaparte, 1971 [sic] = Herpetosuchus Boulenger, 1903 [sic] Genus: Dorosuchus Sennikov, 1989 E. grand Newton, 1894 (Type) D. neoetus Sennikov, 1989 (Type) Genus: Parringtonia von Huene, 1939 Genus: Euporkeria Broom, 1913 P. gracilis von Huene, 1939 (Type) = Brownieila Broom, 1913 = Euparida Thulborn, 1979 [sic] E. capensis Broom, 1913 (Type) Family: ORNITHOSUCHIDAE = Brownieila africana Broom, 1913 von Huene, 1908 Genus: Halazhaisuchus Wu, 1982 H. qiaoensis Wu, 1982 (Type) Census: 6 genera (3 doubtful), Genus: Turfanosuchus Young, 1973 6 species (3 doubtful) T. dabanensis Young, 1973 (Type) Genus: Avalonianus Kuhn, 1961 [nomen dubi- T. shageduensis Wu, 1982 um] Genus: Wangisuchus Young, 1964 = Abalonia Romer, 1966 [sic] W. tzeyii Young, 1964 = Seeley, 1898/Walcott, 1889 [nomen dubium] Genus: Xilousuchus Wu, 1981 = Picrodon Seeley, 1898 [nomen dubium] X. sapingensis Wu, 1981 (Type) A. sanfordi (Seeley, 1898) (Type) = Avalonia sanfordi Seeley, 1898 [nomen dubium]

Thecodontia Owen, 1859 38 Mesozoic Meanderings #2 = Picrodon herveyi Seeley, 1898 [nomen = Omithosuchus woodwardi Newton, 1894 dubium] = Omithosuchus taylori Broom, 1913 Genus: Basutodon von Huene, 1932 [nomen du­ Genus: Bonaparte, 1969 bium] R. tenuisceps Bonaparte, 1969 (Type) B.ferox von Huene, 1932 (Type) Genus: Venaticosuchus Bonaparte, 1971 Genus: Omithosuchus Newton, 1894 V. ntsconii Bonaparte, 1971 (Type) = Dasygnathoides Kuhn, 1961 = Omithosuchus ntsconii (Bonaparte, = Dasygnathus Huxley, 1877/MacLeay, 1819 1971) = Desygnathus Reig, 1961 [sic] Genus: Zatomus Cope, 1871 [nomen dubium] O. longidens (Huxley, 1877) (Type) Z. sarcophagus Cope, 1871 (Type) = Dasygnathus longidens Huxley, 1877 = Dasygnathoides longidens (Huxley, 1877) Genus: [To be described from the Ghost Ranch Quarry; M. Parrish, pers. comm.]

Orden Pseudosuchia Zittel, 1887-90 Census: 4 suborders, 7 families, 50 genera (7 doubtful), 67 species (18 doubtful) Suborder: Archaeosuchia Sill, 1967

Census: 3 families, 7 genera, 8 species Genus: Tropidosuchus Arcucci, 1989 [nomen Family: PROTEROCHAMPSIDAE nudum] Sill, 1967 T. romeri Arcucci, 1989 (Type) NOTE: The above genus and species were Census: 4 genera, 5 species described by A. Arcucci in her 1988 Master's = Cerritosauridae Bonaparte, 1971 degree dissertation but have not yet been for­ mally published. The names appeared in print Genus: Cenitosaurus Price, 1946 in articles by Arcucci in 1989. C. binsfeldi Price, 1946 (Type) Genus: [To be described from the Upper Petri­ Genus: Romer, 1971 fied Forest Member of the ; = Chanaeresuchus Camp & Banks, 1978 [sic] R. A. Long, pers. comm.; Murry & Long, = Chaparesuchus Arcucci, 1989 [sic] 1989] C. bonapartei Romer, 1971 (Type) Genus: Gualosuchus Romer, 1971 G. reigi Romer, 1971 (Type) Family: RHADINOSUCHIDAE Hoffstetter, 1955 Genus: Proterochampsa Reig, 1959 P. banionuevoi Reig, 1959 (Type) Census: 2 genera, 2 species P. nodosa Barberena, 1982 Genus: Procerosuchus von Huene, 1942 P. celer von Huene, 1942 (Type) Genus: Rhadinosuchus von Huene, 1942 R. gracilis von Huene, 1942 (Type)

Parainf raclass Archosauria Cope, 1869 39 Thecodontia Owen, 1859 Genus: Doswellia Weems, 1980 Family: DOSWELUIDAE Weems, 1980 D. kaltenbachi Weems, 1980 (Type) NOTE: This family is classified in this subor­ Census: 1 genus, 1 species der provisionally. Bonaparte (1982) considers = Doswelliinae Weems, 1980 it aetosaurian.

Parasuborden Erythrosuchia Bonaparte, 1982 Census: 1 family, 12 genera (4 doubtful), 16 species (6 doubtful) Genus: Broom, 1905 Parafamily: ERYTHROSUCHIDAE = Erytherosuchus von Huene, 1942 [sic] Watson, 1917 E. africanus Broom, 1905 (Type) E. magnus Ochev, 1980 Census: 12 genera (4 doubtful), 16 species (6 doubtful) Genus: Gamosaurus Ochev, 1979 G. lozovsMi Ochev, 1979 (Type) = Erythrosuchinae Tatarinov, 1961 = Garjainiidae Ochev, 1958 Genus: Garjainia Ochev, 1958 = Shansisuchidae Young, 1964 G. prima Ochev, 1958 (Type) = Shansisuchinae Kuhn, 1966 = Erythrosuchus primus (Ochev, 1958) = Vjushkoviidae von Huene, 1960 = Chasmatosuchus vjushkovi Ochev, 1961 Genus: Chalishevia Ochev, 1980 Genus: Ocoyuntaia Rusconi, 1947 [nomen C. cothumata Ochev, 1980 (Type) dubium] O. arquata Rusconi, 1947 (Type) Genus: Chasmatosuchus von Huene, 1940 = Chasmathosuchus Ochev & Shishkin, Genus: Seemania von Huene, 1958 [nomen 1989 [sic] dubium] = Chasmatosaurus Ochev, 1979/Haughton, S. palaeotriadica von Huene, 1958 (Type) 1924 [sic] Genus: Young, 1959 C. rossicus von Huene, 1940 (Type) = Shanisisuchus Cruickshank, 1979 [sic] ?C. parvus von Huene, 1940 [nomen dubium] S. shansisuchus Young, 1964 (Type) Genus: Crenelosaums Ortlam, 1967 [nomen S. heiyuekouensis Young, 1964 [nomen dubium] dubium] C. nigrosilvanus Ortlam, 1967 (Type) S. kuyeheensis Cheng, 1980 Genus: Cuyosuchus Reig, 1961 Genus: Vjushkovia von Huene, 1960 = Chigutisaurus Rusconi, 1947 (postcranial) = Vjushkoia Reig, 1961 [sic] C. huenei Reig, 1961 (Type) = Vjushkovia von Huene, 1959 [nomen = Chigutisaurus tunuyanensis Rusconi, nudum] 1947 (postcranial) V. triplicostata von Huene, 1960 (Type) = Erythrosuchus triplicostatus (von Huene, Genus: Dongusia von Huene, 1940 [nomen 1960) dubium] D. colorata von Huene, 1940 (Type) Genus: [To be described from Yerrapali, = Erythrosuchus colorants (von Huene, ; Robinson, 1967] 1940) [nomen dubium] Genus: [To be described from the Late Trias- sic of the Soviet Union; Sennikov, 1990]

Thecodontia Owen, 1859 40 Mesozoic Meanderings #2 Parasuborden Rauisuchia Bonaparte, 1982 Census: 1 family, 24 genera (2 ibtful), 34 species (9 doubtful) Genus: Luperosuchus Romer, 1971 Family: RAUISUCHIDAE Price, 1946 Lfractus Romer, 1971 (Type) Census: 20 genera, 23 species Genus: Mandasuchus Charig vide Krebs, 1976 = Mandasuchus Charig, 1956 [nomen = Prestosuchidae Romer, 1966 nudum] = Raisuchidae Reig, 1961 [sic] = Mandasuchus Charig, 1967 [nomen = Rauisuchinae Von Huene, 1936 nudum] [nomen nudum] M. tanyauchen Charig vide Krebs, 1976 = Rauisuchinae Von Huene, 1938 (Type) [nomen nudum] = Mandasuchus tanyauchen Charig, 1967 = Rauisuchinae von Huene, 1942 [nomen nudum] Genus: Bromsgroveia Galton, 1985 Genus: Charig, 1967 [nomen B. walked Gallon, 1985 (Type) nudum] Genus: Dongusuchus Sennikov, 1988 = Nyasaums White, 1973 [sic] = Donguchus Sennikov, 1990 [sic] N. cromptoni Charig, 1967 (Type) D. efremovi Sennikov, 1988 (Type) Genus: von Huene, 1942 Genus: Energosuchus Ochev, 1986 P. chiniquensis von Huene, 1942 (Type) = Energosuchus Ochev, 1982 [nomen P. toricatus von Huene, 1942 nudum] Genus: von Huene, 1942 E. garjainovi Ochev, 1986 (Type) = Rauisuchus von Huene, 1936 [nomen Genus: Fasolasuchus Bonaparte, 1981 nudum] = Fasolasuchus Bonaparte, 1978 [nomen = Rauisuchus von Huene, 1938 [nomen nudum] nudum] - Fasolosuchus Galton, 1985 [sic] R. tiradentes von Huene, 1942 (Type) F. tenax Bonaparte, 1981 (Type) = Rauisuchus tiradentes von Huene, 1938 = Fasolasuchus tenax Bonaparte, 1978 [nomen nudum] [nomen nudum] Genus: Reig, 1959 Genus: Fenhosuchus Young, 1964 = Saurosuchos Reig, 1961 [sic] = Fenchosuchus Sennikov, 1988 [sic] = Saurusochus Reig, 1961 [sic] F. cristatus Young, 1964 (Type) S. galilei Reig, 1959 (Type) = Saurusochus galilei Reig, 1961 [sic] Genus: Heptasuchus Dawley, Zawiskie & Cosgriff, 1979 ( = ?) Genus: Stagonosuchus von Huene, 1938 H. clarki Dawley, Zawiskie & Cosgriff, 1979 S. major (Haughton, 1932) (Type) (Type) = Stenaulomynchus major Haughton, 1932 = Stagonosuchus nyassicus von Huene, Genus: Jaikosuchus Sennikov, 1990 1938 /. magnus (Ochev, 1979) (Type) = Stagonosuchus tanganyikaensis = Chasmatosuchus magnus Ochev, 1979 Boonstra, 1953 Genus: Jushatyria Sennikov, 1985 Genus: Krebs, 1965 /. vjushkovi Sennikov, 1985 (Type) T.ferox Krebs, 1965 (Type)

Parainfraclass Archosauria Cope, 1869 41 Thecodontia Owen, 1859 Genus: Tikisuchus Chatterjee & Majumdar, Stutchbury, 1836 [nomen dubium] 1987 = Thecodontosaurus cylindrodon (Riley & = Tikisuchus Chatterjee & Hotton, 1986 Stutchbury, 1836) von Huene, 1908 [nomen nudum] [nomen dubium] T. romeri Chatterjee & Majumdar, 1987 = Palaeosaurus cylindricum Riley & (Type) Stutchbury, 1836 [sic] ?P. platyodon (Riley & Stutchbury, 1836) Genus: Tsylmosuchus Sennikov, 1990 [nomen dubium] = Thecodontosauius Yakovlev, 1916 non = Palaeosaurus platyodon Riley & Riley & Stutchbury, 1836 Stutchbury, 1836 [nomen dubium] T. jakovlevi Sennikov, 1990 (Type) - Rileya platyodon (Riley & Stutchbury, T. samariensis Sennikov, 1990 1836) [nomen dubium] T. donensis Sennikov, 1990 = Thecodontosaurus platyodon (Riley & Genus: Vjushkovisaurus Ochev, 1982 Stutchbury, 1836) von Huene, 1908 V. berdjanensis Ochev, 1982 (Type) [nomen dubium] NOTE: The above species is probably a pa- Genus: Vytshegdosuchus Sennikov, 1988 rasuchian. V. zheshartensis Sennikov, 1988 (Type) ?P. stricklandi (Davis, 1881) [nomen dubium] Genus: Youngosuchus Sennikov, 1985 = Palaeosaurus stricklandi Davis, 1881 Y. sinensis (Young, 1973) [nomen dubium] = Vjushkovia sinensis Young, 1973 NOTE: The above species is probably a pa- = Vjushkovia sinensia Young, 1973* rasuchian. ?P. subcylindrodon (von Huene, 1908) Genus: (To be described from Kupferzell, Ger­ [nomen dubium] many, Wild, 1980] = Thecodontosaurus subcylindrodon von Genus: [To be described from Bukobay, Soviet Huene, 1908 [nomen dubium] Union; Ochev, 1979; Sennikov, 1990] = Palaeosaurus subcylindrodon (von Huene, 1908) [nomen dubium] NOTE: The above species may be a herrera- RAUISUCHIA incertae sedis saurian (cf. Gallon, 1984). Genus: Pallisteria Charig, 1967 [nomen nudum] Census: 4 genera (2 doubtful), P. angustimentum Charig, 1967 (Type) 11 species (9 doubtful) Genus: Spinosuchus von Huene, 1932 = Palaeosauridae von Huene, 1932 = Spinosaurus Chatterjee, 1986/Stromer, = Palaeosauriscidae Kuhn, 1959 1915 [sic] = Pallisteriidae Charig, 1967 S. caseanus von Huene, 1932 (Type) [nomen nudum] = Zanclodorrtidae Marsh, 1882 Genus: Plieninger, 1846 [nomen dubium] Genus: Gracilisuchus Romer, 1972 = Smilodon Plieninger, 1846/Lund, 1842 G. stipanicicorum Romer, 1972 (Type) Z. laevis (Plieninger, 1846) (Type) Genus: Palaeosauriscus Kuhn, 1959 [nomen = Smilodon laevis Plieninger, 1846 dubium] [nomen dubium] = Palaeosaurus Riley & Stutchbury, = Zanclodon plieningeri E. Fraas, 1896 1836/Geoffroy Saint-Hilaire, 1833 [nomen [nomen dubium] dubium] ?Z. crenatus (Plieninger, 1846) [nomen P. cylindrodon (Riley & Stutchbury, 1836) dubium] (Type) = Smilodon crenatus Plieninger, 1846 = Palaeosaurus cylindrodon Riley & [nomen dubium]

Thecodontia Owen, 1859 42 Mesozoic Meanderings #2 ?Z. bavaricus E. Fraas vide Sandberger, 1894 = Megalosaurus silesiacus (Jaekel, 1910) [nomen dubium] [nomen dubium] ?Z. schutzii E. Fraas, 1900 [nomen dubium] NOTE: The above genus is not thecodontian - schutzii (E. Fraas, 1900) and will be redescribed by Galton & Sues (P. [nomen dubium] M. Galton, pers. comm.). ?Z. silesiacus Jaekel, 1910 [nomen dubium] Suborder; Poposauria nov.

Census: 1 family, 5 genera (1 doubtful), 6 species (2 doubtful) = Lythrodynastes Trimble, 1984 [nomen Family: TERATOSAURIDAE Cope, 1871 nudum] P. kirkpatricki Chatterjee, 1985 (Type) Census: 5 genera (1 doubtful), NOTE: A Chinle Formation teratosaurid, to 6 species (2 doubtful) have been named Lythrodynastes (R. A. Long, = Poposauridae Nopcsa, 1928 pers. comm.), is now considered to be synony­ mous with this Dockum Formation genus. The Genus: Arizonasaurus Welles, 1947 name of the Chinle "genus" has appeared in A. babbitti Welles, 1947 (Type) print with various spellings but without formal description. The Postosuchus material is actual­ Genus: "Chatterjeea" Murry & Long, 1989 [to ly composite and includes at least one other po- be described] posaurid genus and species; see "Chatterjeea" "C. elegans" Murry & Long, 1989 [to be above. described] NOTE: This species is to be based on part Genus: Teratosaurus von Meyer, 1861 of the Postosuchus kirkpatricki type specimen, = Cladeiodon Owen, 1841 which is now known to be composite. See Note = Claderodon Agassiz, 1846 [sic] for Postosuchus below. = Cladyodon Owen, 1842 [sic] Genus: Dolichobrachium Williston, 1904 = Kladeisteriodon Plieninger, 1846 [sic] [nomen dubium] = KLadyodon Plieninger, 1846 [sic] D. gracile Williston, 1904 (Type) T. suevicus von Meyer, 1861 (Type) = Cladeiodon lloydii Owen, 1841 Genus: Poposaurus Mehl, 1915 = Claderodon lloydii (Owen, 1841) P. gracilis Mehl, 1915 (Type) = Cladyodon lloydii (Owen, 1841) = Poposaurus agilis Galton, 1977 [sic] = Kladeisteriodon lloydii (Owen, 1841) [New species to be described from the Pa- = Kladyodon lloydii (Owen, 1841) leorhinus horizon of the Lower Dockum = Teratosaurus lloydii (Owen, 1841) Formation of the southwestern United TT. bengalensis Das-Gupta, 1929 [nomen States; R. A. Long, pers. comm.] dubium] Genus: Postosuchus Chatterjee, 1985 NOTE: Reference of this genus by Galton = Lythodynastes Lufkin vide Dedera, 1983 (1985) to the same family as Poposaurus man­ [nomen nudum] dates the use of Teratosaundae as the family = Lythrodynaestes Ash, 1985 [nomen name instead of Poposauridae. nudum; sic]

Parainfraclass Archosauria Cope, 1869 43 Thecodontia Owen, 1859 Pseudosuchia incertae sedis

Census: 1 family, 2 genera, 3 species (1 doubtful) Genus: Lotosaums Zhang, 1975 Family: CTENOSAURISCIDAE L. adentus Zhang, 1975 (Type) Kuhn, 1964

Census: 2 genera, 2 species Family:TELEOCRATER!DAE = Ctenosauridae Kuhn, 1961 Romer, 1966 [nomen nudum] = Lotosauridae Zhang, 1975 Census: 0 genera, 1 doubtful species Genus: Ctenosauriscus Kuhn, 1964 = Ctenosaurus von Huene, 1902/Fitzinger, Genus: Teleocruter Charig, 1956 [nomen 1843 nudum] C. koeneni (von Huene, 1902) (Type) ?T. olophos (Haughton, 1932) [nomen = Ctenosaurus koeneni von Huene, 1902 dubium] = Thecodontosaurus alophos Haughton, Genus: Hypselorhachis Charig, 1967 [nomen 1932 [nomen dubium] nudum] T. rhadinus Charig, 1967 (Type) H. mirabilis Charig, 1967 (Type) NOTE: This undescribed genus and family NOTE: This species is supposed to possess are referred to this order provisionally. vertebrae with tall neural spines.

Orden Parasuchia Huxley, 1875 Census: 1 family, 23 genera (16 doubtful), 56 species (32 doubtful) Gregory, 1962 [nomen dubium] Family: PARASUCHIOAE — riitimeyeri (von Huene, 1911) Lydekker, 1885 Gregory, 1962 [nomen dubium]* Census: 23 genera (16 doubtful), Genus: Mehl, 1913 56 species (32 doubtful) = Angustorhinus Ochev & Shishkin, 1989 [sic] = Angistorhininae Camp, 1930 = Brachysuchus Case, 1929 = Mystriosuchidae von Huene, 1915 A. grandis Mehl, 1913 (Type) = Mystriosuchinae Chatterjee, 1978 A. gracilis Mehl, 1915 = Parasuchinae Chatterjee, 1978 A. maximus Mehl, 1928 = Phytosauridae Lydekker, 1888 ?A. megalodon (Case, 1929) Gregory, 1969 = Phytosaurinae Camp, 1930 = Brachysuchus megalodon Case, 1929 Genus: Angistorhinopsis von Huene, 1922 = megalodon (Case, 1929) [nomen dubium] Gregory, 1962 A. ruetimeyeri (von Huene, 1911) (Type) A. alticephalus Stovall & Wharton, 1936 = Angistorhinopsis riitimeyeri (von Huene, A. aeolamnis Eaton, 1965 1911) [nomen dubium]* A. talainti Dutuit, 1977 = ruetimeyeri von Huene, Genus: von Meyer, 1842 1911 [nomen dubium] = Beldon Mehl, 1915 [sic] = Mystriosuchus riitimeyeri von Huene, = Belondon Gregory, 1962 [sic] 1911 [nomen dubium]* B. plieningeri von Meyer, 1842 (Type) = Rutiodon ruetimeyeri (von Huene, 1911)

Thecodontia Owen, 1859 44 Mesozoic Meanderings #2 = Mystriosuchus plieningeri (von Meyer, = Palaeosaurus priscus (Leidy, 1856) 1842) von Huene, 1911 [nomen dubium] = Phytosaunts plieningeri (von Meyer, = Phytosaurus priscus (Leidy, 1856) 1842) [nomen dubium] = Mystriosuchus ingens E. Fraas, 18% Genus: Eurydorus Leidy, 1859 [nomen dubium; = Belodon ingens (E. Fraas, 1896) = Rutiodonl] = Belondon plieningeri (von Meyer, 1842) E. serridens Leidy, 1859 (Type) Gregory, 1962 [sic] = Belodon serridens (Leidy, 1859) [nomen ?B. Upturns Cope, 1870 [nomen dubium] dubium] = Phytosaurus lepturus (Cope, 1870) = Clepsysaums serridens (Leidy, 1859) [nomen dubium] Case, 1930 [nomen dubium] ?B. arenaceus (E. Fraas, 1896) [nomen dubi­ = Phytosaurus serridens (Leidy, 1859) [no­ um] men dubium] = Zanclodon arenaceus E. Fraas, 18% [no­ men dubium] Genus: Heterodontosuchus Lucas, 1898 [nomen = Mystriosuchus arenaceus (E. Fraas, dubium] 18%) [nomen dubium] H. ganei Lucas, 1898 (Type) = Phytosaurus arenaceus (E. Fraas, 18%) = ganei (Lucas, 1898) West- [nomen dubium] phal, 1976 [nomen dubium] = Phytosaurus ganei (Lucas, 1898) Greg­ Genus: Centemodon Lea, 1856 [nomen dubium] ory, 1%2 [nomen dubium] C. sulcatus Lea, 1856 (Type) = sulcatus (Lea, 1856) [nomen Genus: Mesorhinosuchus Kuhn, 1%1 [nomen dubium] dubium; — Paleorhinus?] = Rudodon sulcatus (Lea, 1856) [nomen = Mesorhinus Jaekel, 1910/Ameghino, 1885 dubium] [nomen dubium] NOTE: The above genus may not be a para- M.fraasi (Jaekel, 1910) (Type) suchian (Weems, 1980). = Mesorhinus fraasi Jaekel, 1910 [nomen dubium] Genus: Clepsysaums Lea, 1851 [nomen dubium; = Rutiodonl] Genus: Mystriosuchus E. Fraas, 18% = Clepsisaurus Emmons, 1856 [sic] M. planirostris (von Meyer, 1863) (Type) = Clepysaurus Kuhn, 1933 [sic] = Belodon planirostris von Meyer, 1863 C. pennsylvanicus Lea, 1851 (Type) = Phytosaurus planirostris (von Meyer, 1863) = Phytosaurus pennsylvanicus (Lea, 1851) Gregory, 1%2 [nomen dubium] Genus: Nicrosaurus O. Fraas, 1866 = Rudodon pennsylvanicus (Lea, 1851) = Lophoprosopus Mehl, 1915 [nomen dubium] = Lophorhinus Mehl, 1915 [sic] C. veatleianus Cope, 1877 [nomen dubium] — Microsaurus Romer, 1956/DeJean, 1833 [sic] Genus: Coburgosuchus Heller, 1954 [nomen N. kapffi (von Meyer, 1861) (Type) dubium] = Belodon kapffi von Meyer, 1861 = Coburgosaurus Heller, 1954 [sic] = Lophoprosopus kapffi (von Meyer, 1861) C. goeckeli Heller, 1954 (Type) Mehl, 1915 = Phytosaurus goeckeli (Heller, 1954) = Lophorhinus kapffi (von Meyer, 1861) [nomen dubium] Mehl, 1915 [sic] = Phytosaurus kapffi (von Meyer, 1861) Genus: Compsosaurus Leidy, 1856 [nomen = Phytosaurus kapfi Gregory, 1%2 [sic] dubium; = Rutiodon?] = Belodon kapffi Hunt & Lucas, 1989 [sic] C. priscus Leidy, 1856 (Type) = Belodon priscus (Leidy, 1856) [nomen ?N. superciliosus (Cope, 1893) [nomen dubi­ dubium] um]

Parainfraclass Archosauria Cope, 1869 45 Thecodontia Owen, 1859 = Belodon superciliosus Cope, 1893 [no­ liston, 1904) Chatterjee, 1978 men dubium] = Promystriosuchus ehlersi Case, 1922 = Phytosaurus superciliosus (Cope, 1893) [nomen dubium] [nomen dubium] = Paleorhinus ehlersi (Case, 1922) Grego­ ?N. validus (Marsh, 1893) [nomen nudum] ry, 1962 [nomen dubium] = Belodon validus Marsh, 1893 [nomen nu­ = Paleorhinus (Paleorhinus) ehlersi (Case, dum] 1922) Westphal, 1976 [nomen dubium] = validus (Marsh, = (Paleorhinus) ehlersi (Case, 1893) [nomen nudum] 1922) Chatterjee, 1978 [nomen dubium] = Phytosaurus validus (Marsh, 1893) [no­ = Paleorhinus parvus Mehl, 1928 men nudum] = Paleorhinus (Paleorhinus) parvus (Mehl, 1928) Westphal, 1976 Genus: Omosaums Leidy, 1856 [nomen = Parasuchus (Paleorhinus) parvus (Mehl, dubium; = Rutiodon?] 1928) Chatterjee, 1978 O. perplexus Leidy, 1856 (Type) = Paleorhinus scurriensis Langston, 1949 Genus: Pachysuchus Young, 1951 [nomen = Paleorhinus (Paleorhinus) scurriensis dubium] (Langston, 1949) Westphal, 1976 P. imperfectus Young, 1951 (Type) =Parasuchus (Paleorhinus) scurriensis = Pachysuchus imperfecta Young, 1951 (Langston, 1949) Chatterjee, 1978 [nomen dubium]* ?P. broilii (Kuhn, 1932) Gregory, 1962 [no­ men dubium] Genus: Palaeoctonus Cope, 1877 [nomen = Francosuchus broilii Kuhn, 1932 dubium; = Rxitiodonl] = Paleorhinus (Francosuchus) broilii = Palaeochtinus Mehl, 1915 [sic] (Kuhn, 1962) Westphal, 1976 = Palaeoctomus von Huene, 1902 [sic] = Francosuchus loots Kuhn, 1932 P. appalachianus Cope, 1877 (Type) = Paleorhinus latus (Kuhn, 1932) P. aulacodus Cope, 1878 [nomen dubium] = Paleorhinus (Francosuchus) latus — Suchoprion aulacodus (Cope, 1878) [nomen dubium] (Kuhn, 1932) Westphal, 1976 P. dumblianus Cope, 1893 [nomen dubium] = Ebrachosuchus angustifrons Kuhn, 1936 = Nicrosaurus dumblianus (Cope, 1893) = Francosuchus angustifrons (Kuhn, 1936) WestphaL 1976 [nomen dubium] = Paleorhinus angustifrons (Kuhn, 1936) = Phytosaurus dumblianus (Cope, 1893) = Paleorhinus (Francosuchus) angustifrons Gregory, 1962 [nomen dubium] (Kuhn, 1936) Westphal, 1976 P. orthodon Cope, 1893 [nomen dubium] = Mystriosuchus plieningeri Kuhn, 1936 = Nicrosaurus orthodon (Cope, 1893) non (von Meyer, 1842) [nomen dubium] P. neukami (Kuhn, 1936) Gregory, 1962 = Ebrachosuchus neukami Kuhn, 1936 = Phytosaurus orthodon (Cope, 1893) = Francosuchus neukami (Kuhn, 1936) Gregory, 1962 [nomen dubium] = Paleorhinus (Francosuchus) neukami Genus: Paleorhinus Williston, 1904 (Kuhn, 1936) Westphal, 1976 = Ebrachosuchus Kuhn, 1936 ?P. trauthi (von Huene, 1939) [nomen = Francosuchus Kuhn, 1932 [nomen dubium] dubium] = Francosuchus trauthi von Huene, 1939 = Palaeorhinus Jaekel, 1910 [sic] [nomen dubium] = Promystriosuchus Case, 1922 [nomen = Paleorhinus (Francosuchus) trauthi (von dubium] Huene, 1939) Westphal, 1976 [nomen du­ P. bransoni Williston, 1904 (Type) bium] = Paleorhinus (Paleorhinus) bransoni (Wil­ P. magnoculus Dutuit, 1977 liston, 1904) Westphal, 1976 = Parasuchus (Paleorhinus) magnoculus = Parasuchus (Paleorhinus) bransoni (Wil­ (Dutuit, 1977) Chatterjee, 1978

Thecodontia Owen, 1859 Mesozoic Meanderings #2 P. hislopi Hunt & Lucas, 1991 = Phytosaurus maleriensis (von Huene, = Parasuchus (Paieorhinus) hislopi Chat- 1940) Colbert, 1958 [nomen dubium] terjee, 1978 non (Lydekker, 1885) NOTE: See Note for Paieorhinus. NOTE: Gregory (1962) partitioned Paieorhi­ Genus: Phytosaurus Jaeger, 1828 [nomen nus into two subgenera, Paieorhinus and Fran­ dubium] cosuchus, the latter containing all the species — Cubicodon Jaeger, 1828 [sic] previously included in the genera Francosuchus = Cylindricodon Jaeger, 1828 [sic] and Ebrachosuchus. Westphal (1976) followed P. cylindricodon Jaeger, 1828 (Type) Gregory and wrote the species names explicitly = Belodon cylindricodon (Jaeger, 1828) using subgeneric notation, which Gregory did [nomen dubium] not do. Chatterjee (1978), however, excluded Francosuchus from synonymy with Paieorhinus = Phytosaurus cylindricon Mehl, 1915 [sic] and considered Paieorhinus to be a junior syno­ ?P. cubicodon Jaeger, 1828 [nomen dubium] nym of Parasuchus, with Parasuchus and Paieo­ — Belodon cubicodon (Jaeger, 1828) rhinus subgenera of Parasuchus. Although Chat­ [nomen dubium] terjee did not do so explicitly in his paper, this = Phytosaurus cubicron Mehl, 1915 [sic] placed all species of Paieorhinus into the sub­ Genus: Pseudopalatus Mehl, 1928 (= Mystrio- genus Parasuchus (Paieorhinus). Hunt & Lucas suchus?) (1991) revised the genus Paieorhinus and elimi­ = Lophosaurus Hay, 1929/Fitzinger, 1843 nated the subgenera, declaring Parasuchus to [sic] be a nomen dubium but treating it as a proba­ P. pristinus Mehl, 1928 (Type) ble synonym of Paieorhinus on the basis of the = Rutiodon pristinus (Mehl, 1928) material described by Chatterjee (1978). Be­ = Machaeroprosopus tenuis Camp, 1930 cause this would make the doubtful Parasuchus (in part) a senior subjective synonym of Paieorhinus, = Rutiodon tenuis (Camp, 1930) Gregory, however, Parasuchus is considered a separate 1962 (in part) genus to be isolated from synonymy. The skele­ P. buceros (Cope, 1881) tons in Chatterjee (1978) do represent a distinc­ = Belodon buceros Cope, 1881 tive Maleri Formation species of Paieorhinus, = Lophoprosopus buceros (Cope, 1881) which Hunt & Lucas referred to as Paieorhinus = Lophosaurus buceros (Cope, 1881) Hay, hislopi. 1929 [sic] Von Huene (1940) based the name Brachysu- = Machaeroprosopus buceros (Cope, 1881) chus maleriensis on the parasuchian material = Metarhinus buceros (Cope, 1881) Jaekel, originally part of the composite type specimen 1910 of Parasuchus hislopi, so Brachysuchus malerien­ = Nicrosaurus buceros (Cope, 1881) sis must be regarded as an objective junior syn­ Murry & Long, 1989 onym of Parasuchus hislopi. = Phytosaurus buceros (Cope, 1881) = Rutiodon buceros (Cope, 1881) Genus: Parasuchus Huxley, 1870 [nomen = buceros (Cope, 1881) aubium] = Machaeroprosopus tenuis Camp, 1930 P. hislopi Lydekker, 1885 (Type) (in part) = Parasuchus (Parasuchus) hislopi (Lydek­ ker, 1885) Chatterjee, 1978 [nomen dubi- = Rutiodon tenuis (Camp, 1930) Gregory, um] 1962 (in part) P. mccauleyi Ballew, 1989 = Paieorhinus hislopi (Lydekker, 1885) Hunt & Lucas, 1991 [nomen dubium] Genus: Rileyasuchus Kuhn, 1961 [nomen = Brachysuchus maleriensis von Huene, dubium] 1940 [nomen dubium] = Rileya von Huene, 1902/Howard, 1888 = Nicrosaurus maleriensis (von Huene, = Rileyia von Huene, 1902 [sic] 1940) Westphal, 1976 [nomen dubium] = Rylea Mehl, 1915 [sic]

Parainfraclass Archosauria Cope, 1869 47 Thecodontia Owen, 1859 R. bristolensis (von Huene, 1902) (Type) = Clepsysaurus manhattanensis (von = Rileya bristolensis von Huene, 1902 Huene, 1913) [nomen dubium] = Phytosaurus manhattanensis (von = Palaeosaums platyodon Riley & Stutch- Huene, 1913) Gregory, 1962 bury, 1840 non Riley & Stutchbury, 1836 NOTE: The above species is probably a [nomen dubium] large male Rutiodon carolinensis (D. Baird, = Rileya platyodon (Riley & Stutchbury, pers. comm.). 1840) von Huene, 1908 [nomen dubium] = Phytosaurus rostrastus Ballew, 1989 [sic] = Rileya stutchburyi von Huene, 1920 ?R. leaii (Emmons, 1856) [nomen dubium] [nomen dubium] = Clepsisaurus leaii Emmons, 1856 = Rileya stutchburi von Huene, 1920 [nomen dubium] [nomen dubium]* = Belodon leaii (Emmons, 1856) [nomen dubium] Genus: Rutiodon Emmons, 1856 = Phytosaurus leaii (Emmons, 1856) = Case, 1922 [nomen dubium] = Machaeorprosopus Gregory, 1962 [sic] ?R, scolopax (Cope, 1881) Gregory, 1962 = Machaeroprosopus Mehl, 1916 [nomen dubium] = Metarhinus Jaekel, 1910/Osbom, 1908 = Belodon scolopax Cope, 1881 [nomen = Palaeonomis Emmons, 1857 dubium] = Rhytidiodon Cope, 1866 [sic] = Phytosaurus scolopax (Cope, 1881) = Rhytidodon Cope, 1866 [sic] McGregor, 1906 [nomen dubium] = Rhytiodin Mehl, 1915 [sic] = Belodon scopax Mehl, 1915 [sic] = Rhytiodon Cope, 1866 [sic] = Lophorhinus scopax Mehl, 1915 [sic] R. carolinensis Emmons, 1856 (Type) = Palaeorhinus scopax Mehl, 1915 [sic] = Belodon carolinensis (Emmons, 1856) ?R. validus (Mehl, 1916) [nomen dubium] = Mystriosuchus carolinensis (Emmons, = Machaeroprosopus validus Mehl, 1916 1856) non (Marsh, 1893) [nomen dubium] = Palaeosaums carolinensis (Emmons, = Clepsysaurus validus (Mehl, 1916) 1856) {nomen dubium] = Phytosaurus carolinensis (Emmons, = Phytosaurus validus (Mehl, 1916) 1856) Gregory, 1962 [nomen dubium] = Rhytidodon carolinensis (Emmons, 1856) R. doughtyi (Case, 1920) Gregory, 1962 = Rhytiodin carolinensis (Emmons, 1856) = Phytosaurus doughtyi Case, 1920 = Palaeonomis struthionoides Emmons, = Machaeroprosopus doughtyi (Case, 1857 1920) Case, 1930 NOTE: The above genus and species were ?R. gracilis (Case, 1920) [nomen nudum] originally described as avian, but the type speci­ = Machaeroprosopus gracilis Case, 1920 men clearly "consists of the mid-section of a rostrum of a phytosaur (cf. Rutiodon)" (D. [nomen nudum] Baird, quoted in Brodkorb, 1978). It was re­ R. andersoni (Mehl, 1922) Gregory, 1962 cently figured by Baird (1986; The Mosasaur 3: [nomen dubium] 139). = Machaeroprosopus andersoni Mehl, 1922 [nomen dubium] = Rhytidodon rostratus Marsh, 1896 R. crosbiensis (Case, 1922) Gregory, 1962 = Mystriosuchus rostratus (Marsh, 1896) = Leptosuchus crosbiensis Case, 1922 = Phytosaurus rostratus (Marsh, 18%) = Leptosuchus imperfectus Case, 1922 McGregor, 1906 [nomen dubium] = Rutiodon rostratus (Marsh, 1896) = Leptosuchus imperfecta Case, 1922 = Rutiodon manhattanensis von Huene, [nomen dubium]* 1913 = Rutiodon imperfectus (Case, 1922) Gregory, 1962 [nomen dubium]

Thecodontia Owen, 1859 Mesozoic Meanderings #2 = Rutiodon imperfecta (Case, 1922) Genus: Suchoprion Cope, 1877 [nomen dubium] Gregory, 1962 [nomen dubium]* S. cyphodon Cope, 1877 (Type) = Leptosuckus studeri Case & White, 1934 = Palaeoctonus cyphodon (Cope, 1877) = Rutiodon studeri (Case & White, 1934) [nomen dubium] Gregory, 1962 ?S. sukidens Cope, 1878 [nomen dubium] R. adamanensis (Camp, 1930) Gregory, 1962 Genus: Termatosaurus von Meyer & Plieninger, = Machaeroprosopus adamanensis Camp, 1930 1844 [nomen dubium; = Belodonl] R. gregorii (Camp, 1930) Ballew, 1989 T. albertii von Meyer & Plieninger, 1844 = Machaeroprosopus gregorii Camp, 1930 (Type) = Nicrosaurus gregorii (Camp, 1930) Greg­ = Mystriosuchus albertii (von Meyer & ory, 1969 Plieninger, 1844) E. Fraas, 18% [nomen dubium] = Phytosaurus gregorii (Camp, 1930) = Termatosaurus alberti Gregory, 1962 [sic] Gregory, 1962 TT. crocodilinus Quenstedt, 1858 [nomen R. lithodendrorum (Camp, 1930) Gregory, dubium] 1962 = Machaeroprosopus lithodendrorum Genus: [To be described; an "advanced" genus; Camp, 1930 Gregory, 1957; Hunt, 1991] R. zunii (Camp, 1930) Gregory, 1962 = Machaeroprosopus zunii Camp, 1930

Orden Aetosauria Nicholson & Lydekker, 1889 Census: 1 family, 16 genera (3 doubtful), 19 species (5 doubtful) Genus: Casamiquela, 1960 Family: STAGONOLEPIDIDAE = Aetosaurioides Reig, 1961 [sic] Lydekker, July 18S7 A. scagliai Casamiquela, 1960 (Type) = Aetosaurioides scagliai Reig, 1961 [sic] Census: 15 genera (2 doubtful), 18 species A. inhamandensis Zacarias, 1982 vide Bar- (4 doubtful) berena, Araujo & Lavina, 1985 [nomen = Stagonolepidae Agassiz, 1844* nudum] = Aethosauridae Baur, September 1887 A. subsulcatus Zacarias, 1982 vide Bar- = Aetosauridae Cope, 1889 berena, Araujo & Lavina, 1985 [nomen = Oesmatosuchinae von Huene, 1942 nudum] = Episcoposaurinae von Huene, 1942 Genus: O. Fraas, 1877 = Stagonolepidiidae Bonaparte, 1971 [sic] = Aetosaurus O. Fraas, 1877* = Stagonolepinae von Huene, 1942 [sic] = Aeotsaurus Reig, 1961 [sic] Genus: Acompsosaurus Mehl, 1915 [nomen du­ A. ferratus O. Fraas, 1877 (Type) bium; — Stagonoiepis!) = Aetosaurus ferratus O. Fraas, 1877* A. wingatensis Mehl, 1915 (Type) A. crassicauda E. Fraas, 1907 = Typothorax wingatensis (Mehl, 1915) = Aetosaurus crassicauda E. Fraas, 1907* [nomen dubium] Genus: Argentinosuchus Casamiquela, 1960 NOTE: The type specimen is lost (Long & A. bonapartei Casamiquela, 1960 (Type) Ballew, 1985). Hunt & Lucas (1989) assert that the figured type material most closely resem­ Genus: Chilenosuchus Casamiquela, 1980 bles Stagonoiepis (but not Typothorax), of Cforttae Casamiquela, 1980 (Type) which the genus may be a junior synonym.

Parainfraclass Archosauria Cope, 1869 49 Thecodontia Owen, 1859 Genus: Case, 1920 S. arcuatus arcuatus (Marsh, 18%) Jepsen, D. haplocerus (Cope, 1892) (Type) 1948 = Episcoposaums haplocerus Cope, 1892 S. arcuatus jerseyensis Jepsen, 1948 = Desmatosuchus spurensis Case, 1920 Genus: Typothorax Cope, 1875 Genus: Dyoplax O. Fraas, 1867 = Episcoposaums Cope, 1887 D. arenaceus O. Fraas, 1867 (Type) = Thypothorax Reig, 1961 [sic] = Typothoras Jacobs & Murry, 1980 [sic] Genus: Ebrachosaurus Kuhn, 1936 [nomen T. coccinarum Cope, 1875 (Type) dubium] = Episcoposaums horridus Cope, 1887 E. singularis Kuhn, 1936 (Type) TT. punctulatus Rusconi, 1947 [nomen Genus: Fukangolepis Young, 1978 [nomen dubium] dubium] = Typothorax pustulatus Reig, 1961 [sic] F. barbaros Young, 1978 (Type) Genus: [To be described from the Middle Tri- Genus: Longosuchus Hunt & Lucas, 1990 assic of Tunisia; L. B. Halstead & Stewart, L. meadei (Sawin, 1947) (Type) 1970] = Typothorax meadei Sawin, 1947 Genus: [To be described from the Rutiodon Genus: Bonaparte, 1969 xunii level of the Petrified Forest Member of N. engaeus Bonaparte, 1969 (Type) the Chinle Formation; R. A. Long, pers. co mm.] Genus: Long & Ballew, 1985 P. andressi Long & Ballew, 1985 (Type) = Paratypothorax omatus Murry, 1986 [sic] AETOSAUR1A incertae sedis Genus: Agassiz, 1844 = Caliptosuchus Ash, 1985 [sic] Census: 1 doubtful genus, 1 doubtful species = Cafyptosuchuas Long & Ballew, 1985 [sic] = Catyptosuchus Long & Ballew, 1985 Genus: Adomanasuchus [Anonymous] 1983 = Stagonolepis von Huene, 1902 [sic] [nomen nudum, in Arizona Highways, Febru­ - Steganolepis MehL 1915 [sic] ary 1983] S. robertsoni Agassiz, 1844 (Type) A. rectori [Anonymous] 1983 (Type) S. wellesi (Long & Ballew, 1985) Murry & Genus: Hoplitosuchus von Huene, 1938 [nomen Long, 1989 dubium] = Catyptosuchus wellesi Long & Ballew, = von Huene, 1938/Lucas, 1985 1902 [sic] Genus: Stegomus Marsh, 1896 H. raui von Huene, 1938 (Type) S. arcuatus Marsh, 1896 (Type)

Order: Crocodylia Gmelin, 1788 Census: 4 suborders (listed), 10 families, 27 genera, 30 species (1 doubtful) NOTE: This section of the archosaur taxa their inclusion in a table otherwise devoted to table comprises only the "lower" crocodilians. the non-crocodilian archosaurs is partially justi­ Many of these taxa have at times been classi­ fiable. But the crocodilian suborders Mesosuch- fied as either dinosaurs or thecodontians, so ia and Eusuchia remain excluded.

Thecodontia Owen, 1859 50 Mesozoic Meanderings #2 Suborder: Trialestia Crush, 1984 Census: 1 family, 1 genus, 1 species = Triassolestes romeri Reig, 1963 Family: TRIALESTIDAE Bonaparte, 1982 NOTE: S. Chatterjee has examined the ma­ terial of the above genus and notes that the Census: 1 genus, 1 species crocodile-reversed tarsus precludes it from as­ = Triassolestidae Bonaparte, 1970 signment to the Crocodylia (R. Molnar, pers. comm.). The type specimen may be composite, Genus: Trialestes Bonaparte, 1982 including both theropod and ornithosuchid ma­ = Triassolestes Reig, 1963/Tillyard, 1918 terial as well as crocodilian material. T. romeri (Reig, 1963) (Type) Suborden Sphenosuchia Bonaparte, 1971

Census: 4 families, 11 genera, 12 species = Barbarenasuchus Parrish, 1991 [sic] Family: PEDETICOSAURIDAE B. brasiliensis Mattar, 1987 (Type) van Hoepen, 1915 Genus: Simmons, 1965 Census: 3 genera, 3 species = Dibthrosuchus Dong, 1980 [sic] D. elaphros Simmons, 1965 = Saltoposuchidae Crush, 1984 D. xingsuensis Wu, 1986 Genus: Pedeticosaurus van Hoepen, 1915 Genus: Colbert, 1952 = Pediticosaurus Gow & Kitching, 1988 [sic] H. agilis Colbert, 1952 (Type) P. leviseuri van Hoepen, 1915 (Type) [New species to be described from Texas; R. Genus: Saitoposuchus von Huene, 1921 A. Long, pers. comm.] S. connectens von Huene, 1921 (Type) Genus: Pseudhesperosuchus Bonaparte, 1969 = Saitoposuchus longipes von Huene, 1921 = Pseudohesperosuchus Crush, 1984 [sic] Genus: Crush, 1984 ( = Sai­ P. jachaleri Bonaparte, 1969 toposuchus?) Genus: Haughton, 1915 T. gracilis Crush, 1984 (Type) S. acutus Haughton, 1915 (Type) Genus: Strigosuchus Simmons, 1965 Family: HEMIPROTOSUCHIDAE S. licinus Simmons, 1965 (Type) Crush, 1984 Genus: [To be described from the McCoy Brook Formation of Nova Scotia; Sues & Gal- Census: 1 genus, 1 species ton, 1987] Genus: Hemiprotosuchus Bonaparte, 1969 H. kali Bonaparte, 1969 (Type) Family: LEWISUCHIDAE [ ex Lewisuchinae]

Family: SPHENOSUCHIDAE Census: 1 genus, 1 species von Huene, 1922 = Lewisuchinae Paul, 1988 Census: 6 genera, 7 species Genus: Romer, 1972 Genus: Barberenasuchus Mattar, 1987 L. admixtus Romer, 1972 (Type)

Parainfraclas s Archosauria Cope, 1869 51 Thecodontia Owen, 1859 Parasuborden Protosuchia Mook, 1934 Census: 4 families, 14 genera, 15 species NOTE: See notes for Erythrosuchus and Or- Family: PROTOSUCHIDAE Brown, 1933 thosuchus. Census: 11 genera, 11 species Genus: Orthosuchus Nash, 1968 O. stormbergi Nash, 1968 (Type) = Arcnaeosuchidae Brown, 1933 NOTE: Gow & Kitching (1988) synonymize = Stegomosuchidae von Huene, 1922 this genus with Notochampsa. Genus: Baroqueosuchus Busbey & Gow, 1984 Genus: Brown, 1933 B. haughtoni Busbey & Gow, 1984 (Type) = Archaeosuchus Brown, 1933/Broom, 1905 NOTE: See note for Lesothosuchus. P. richardsoni (Brown, 1933) (Type) Genus: Clarencea Brink, 1959 = Archaeosuchus richardsoni Brown, 1933 = Clarenceia Romer, 1966 [sic] Genus: Stegomosuchus von Huene, 1922 = Clarencia Brink, 1959 [sic] S. longipes (Emerson & Loomis, 1904) = Clarensia Gow & Kitching, 1988 [sic] (Type) C. gracilis Brink, 1959 (Type) = Stegomus longipes Emerson & Loomis, = Clarensia gracilis (Brink, 1959) 1904 NOTE: Gow & Kitching (1988) attempt to revise die spelling of die name of this genus, Genus: [To be described from the McCoy but this is impermissible under ICZN rules. Brook Formation of Nova Scotia (Sues & Olsen, 1987] Genus: Dianosuchus Young, 1982 D. changchiawaensis Young, 1982 (Type) Genus: Eopneumatosuchus Crompton & Family: PLATYOGNATHIDAE Smith, 1980 Simmons, 1965 = Eupneumatosuchus Crush, 1984 [sic] E. colberti Crompton & Smidi, 1980 (Type) Census: 1 genus, 1 species Genus: Erythrochampsa Haughton, 1924 Genus: Platyognathus Young, 1944 E. longipes (Broom, 1904) (Type) P. hsui Young, 1944 (Type) = Notochampsa longipes Broom, 1904 NOTE: Gow & Kitching (1988) synonymize this genus widi Notochampsa. Family: EDENTOSUCHIDAE Young, 1973 Genus: Lesothosuchus Whetstone & Whybrow, 1983 (= Baroqueosuchus!) L. charigi Whetstone & Whybrow, 1983 Census: 1 genus, 1 species (Type) Genus: Young, 1973 NOTE: Gow & Kitching (1988) assert Uiat E. tienshanensis Young, 1973 (Type) die diagnosis of die genus Lesothosuchus is in­ [One or two new species to be described adequate and reject the name in favor of Baro­ from die Glen Canyon Group; Clark & queosuchus, apparently a junior synonym. Fastovsky, 1986] Genus: Microchampsa Young, 1951 Genus: [To be described from the Glen M. scutata Young, 1951 (Type) Canyon Group; Clark & Fastovsky, 1986] Genus: Notochampsa Broom, 1904 N istedana Broom, 1904 (Type)

Thecodontia Owen, 1859 52 Mesozoic Meanderings #2 G. kielanae Osmolska, 1972 (Type) Family: GOBIOSUCHIDAE G. parvus Efimov, 1983 Osm6lska, 1972 [New species to be described from Mon­ golia; Osm61ska, 1972] Census: 1 genus, 2 species

Genus: Osm61ska, 1972 Suborder: Hallopoda Marsh, 1881

Census: 1 family, 1 genus, 2 species (1 doubtful) Genus: Marsh, 1877 Family: HALLOPODIDAE Marsh, 1881 H. victor (Marsh, 1877) (Type) = victor Marsh, 1877 Census: 1 genus, 2 species (1 doubtful) ?H. celerrimus E. Fraas, 1912 [nomen = Hallopidae Carroll, 1988 [sic] dubium] NOTE: This species is probably a synonym Genus: Fruitachampsa [Anonymous] 1986 of triassicus (R. E. Molnar, [nomen nudum, in Earthwatch magazine, pers. comm.). January-February 1986] F. callisoni [Anonymous] 1986 (Type)

Orden Hupehsuchia Young & Dong, 1972 Census: 1 family, 2 genera, 2 species H. nanchangensis Young vide Young & Family: NANCHANGOSAURIDAE Dong, 1972 (Type) Wang, 1959 Genus: Nanchangosaurus Wang, 1959 Census: 2 genera, 2 species N. suni Wang, 1959 (Type)

= Hupehsuchidae Young & Dong, 1972 Genus: [To be described from the Middle Tri- assic Jialingjiang Formation of China; Carroll Genus: Hupehsuchus Young vide Young & & Dong, 1991] Dong, 1972

Thecodontia incertae sedis

Genus: [To be described from the Chinle For­ Genus: [To be described from the Chinle For­ mation; R. A. Long, pers. comm.] mation; R. A. Long, pers. comm.]

Parainfraclass Archosauria Cope, 1869 53 Thecodontia Owen, 1859 Notes and New Taxa

Thecodontia Owen, 1859 54 Mesozoic Meanderings #2 L Pterosaur Phylogeny

N SOME WAYS, despite their extreme adap­ semi-erect stance when grounded (Unwin, Itations for powered flight and their hairlike 1987, 1988; Wellnhofer, 1988). Evidence that insulative "pelage," the pterosaurs comprise they were bipedal (Padian, 1983a, 1983b; Ben­ the most primitive of the archosaurian ciades nett, 1990) seems to me to indicate only that characterized by modified or advanced meso- they could walk bipedally when necessary—for tarsal (AM) ankles. Pterosaur tarsi are very example, to take off from level ground —but small and difficult to study, but it is clear that not that this was their habitual or obligatory they featured reduced calcanea (Wellnhofer, stance. The hind limb in most pterosaur genera 1991: 57), in contrast with the enlarged, tuberal ( is an exception) was approximate­ calcanea of the semi-erect and fully erect theco- ly as long as the forelimb from the shoulder to dontians. Pterosaurs retained a plesiomorphi- die joint between metacarpal IV and the first cally pentadactyl pes (the fifth digit was re­ wing phalanx. This suggests that the hind limbs duced or vestigial in advanced forms) in which lengthened in step with the enlarging forelimb, the metatarsals showed little or no tendency to in turn suggesting that they were of comparable merge into a single unit, as they did in thero- importance in terrestrial locomotion. Addition­ pod dinosaurs. Corresponding to the reduced ally, the pelvis was wide with an imperforate , the pterosaur was also re­ acetabulum, and the hind limbs were outwardly duced, becoming progressively smaller in more directed, slender, and gracile (in contrast to advanced genera until it was entirely lost in the theropods, for example, in which the hind most Cretaceous forms. Reduction of the fibula limbs were downwardly directed and extraordi­ and calcaneum is a synapomorphy that might narily powerful, even in the small forms). unite the pterosaurs with the dinosaur ciades These considerations prompt me to imagine among the archosaurs. that pterosaurs originated independently within Ail known pterosaur genera lacked a man­ one of those all-purpose groups of sprawling dibular fenestra; all other known archosaurs proterosuchians, diverging away from the The- more advanced than proterosuchians possessed codontia like the dinosaurian ciades but per­ a mandibular fenestra (it became secondarily haps even earlier. The existence of hairlike closed in advanced sauropods and ornithischi- "pelage" in a few well-preserved specimens ans but did exist in the primitive ones). It is (Broili, 1927; Sharov, 1971) makes it reasonable possible that the fenestra closed secondarily in to assume that all pterosaurs shared a similar pterosaurs, too, but if so, it is absent even in integument. This, together with their obvious the earliest known forms. In view of the trend specializations for powered flight, is strong evi­ toward lightening of the skull in pterosaurs by dence that pterosaurs were endothermic, tachy- enlargement of the cranial fenestrae, one might metabolic animals much like extant birds. Endo- expect a mandibular fenestra—had it been pre­ thermy may be a synapomorphy uniting ptero­ sent in ancestral pterosaurs—to have widened saurs with die theropodomorph archosaurs. rather than closed. This, in turn, could mean that pterosaur "pel­ Finally, most if not all pterosaurs seem to age" was derived from a stage in the evolution have been quadrupedal with a sprawling or of feathers (but see the discussion of Sharovip-

Parairrfraclass Archosauria Cope, 1869 55 Pterosaur Phylogeny teryx that follows). Lack of any specimens iden­ orbital fenestra could well be lost. It is also pos­ tifiable as ancestral pterosaurs prior to the sible that the fenestra merged with the narial Late Triassic, however, when they appear ab­ opening as in later pterosaurs, because Gans, ruptly and well evolved in the fossil record of et al. report long and slender nares in Sharovip­ , makes further comment on their ori­ teryx. Finally, they report skin impressions that gins highly speculative. Recent cladistic analy­ show small keeled scales along the back, not ses (cf. Benton, 1990a) confirm the Pterosauria the hairlike "pelage" of pterosaurs. If Sharovip­ as a sister group to the dinosaurian clades, but teryx were indeed a derived pre-pterosaur, then for reasons stated earlier and elaborated in the pterosaur "pelage" and feathers must have orig­ Dinosaur Phylogeny section, I do not accept inated independently. the pterosaur-dinosaur clade as being particu­ The primary lift forces in pre-pterosaurs larly closely related to the Ornithosuchia. were almost certainly generated by lateral pa- (This, incidentally, may also mean that the man­ tagjal membranes stretching along the sides of dibular fenestra developed independently in the body between the forelimbs and hind thecodontians and in dinosaurs.) limbs, as illustrated by Peters & Gutmann. Such membranes could have continued back­ ward to envelop the hind limbs or tail in a uro­ PTEROSAUR FLIGHT patagium, but if so, it was lost early in the line­ age leading to the traditional pterosaur orders. The vast structural differences between pter­ A gliding pre-pterosaur would have resembled osaur and avian wings make it obvious that a reptilian flying squirrel, and the gradual en­ flight arose independently within the two largement of the aftmost manual digits to sup­ groups. Nevertheless, there were undoubtedly port larger and more efficient membraneous functional similarities in how this occurred in wings seems the most natural way for the ptero­ the groups, the result of aerodynamic con­ saurs to have evolved. straints on vertebrate anatomy (Peters & Gut- Encumbered by their wing membranes, mann, 1985). which almost certainly involved fore and hind Most pterosaur specimens that display wing limbs, the earliest pterosaurs would have been impressions seem never to show traces of a tail unable to evolve a fully erect bipedal stance. In membrane, although pilosus evidently later pterosaurs, the hind limb and pelvis had retained one (Sharov, 1971; Wellnhofer, 1991). become highly adapted to a semi-erect stance So there may have been a uropatagial stage at that probably did not allow more than a faculta­ some early time in pterosaur evolution. In tive bipedality, even though the wing mem­ 1971, Sharov reported a peculiar gliding reptile brane may actually have been free of the hind from the of central Russia in which the limb. Lacking a secondary locomotor ability, principal aerodynamic surface was an extensive pterosaurs would seldom have evolved flight­ uropatagium. It is possible that Sharovipteryx less forms, in marked contrast to avian evolutio­ (originally called Podopteryx) might have been nary history. a derived uropatagial pterosaurian. Recently re- Pterosaurs were clearly a very diverse group described by Gans, Darevski & Tatarinov of archosaurs, of which we have good samples (1987), Sharovipteryx possessed several charac­ from only a handful of localities. At Solnhofen, ters suggesting a relationship with the ptero­ for example, pterosaurs outnumber archaeop- saurs, including a reduced fibula, a pentadactyl terygids by scores of species to one. I have no pes, and a lacking a fenestra. It may doubt that a naturalist thrust back in time to also have had a prepubic bone, which is a pter­ any epoch of the Jurassic or Cretaceous would osaur autapomorphy. But Gans, et al. report no find pterosaurs nearly as common and diverse antorbital fenestra, which would remove Sha­ as modern birds. Competition from pterosaurs rovipteryx from the Archosauria. The skull of undoubtedly restricted avian diversification un­ the only available specimen, however, is split til birds became more efficient fliers than pter­ apart horizontally, and evidence for an ant­ osaurs, sometime before the Early Cretaceous

Pterosaur Phylogeny 56 Mesozoic Meanderings #2 (when the fully volant Chinese birds appeared). ative to body, very small forelimbs and enor­ Thereafter, birds slowly replaced the smaller mously long hind limbs—it is remarkably simi­ pterosaurs. When the large pterosaurs became lar to Sharovipteryx; all that is needed is the extinct at the end of the Mesozoic, there were trace of a uropatagium to completely confirm no small pterosaurs from which new groups their phyletic closeness. The spe­ could radiate, and the establishment of birds as cimens illustrated by Huene bear a remarkable the dominant aerial vertebrates was complete. superficial resemblance to the Sharovipteryx type specimen. Huene described a robust cal- caneum in Scleromochlus, and his sketch of the PTEROSAUR ORDERS animal (reproduced in Wellnhofer, 1991) shows a fenestrated mandible, but I think these deter­ In view of pterosaurs' early divergence from minations are questionable (Padian [1984] the other archosaurs and the specializations for noted a mesotarsal ankle for Scleromochlus). In flight that affected every part of their anatomy, the table, I have synonymized the family Sharo- raising the traditional order Pterosauria to a su­ vipterygidae with Huene's Scleromochlidae and perorder on a taxonomic par with the Theco- classified it in the Sharoviptervgia. A redescrip- dontia and the three dinosaurian groups is cer­ tion of Scleromochlus is required to confirm or tainly justified. As such it forms a clade partitio- deny this assignment. nable into two or three ordinal-level taxa. These are discussed individually below. Paraorder Rhamphorhvnchoidia Regarding the pterosaurs, a marvelous book The two traditional suborders of the Ptero­ (Wellnhofer, 1991) was recendy published that sauria are here raised to orders within the su­ covers the group from all aspects: phyletic, tax­ perorder. As more pterosaur specimens are col­ onomic, anatomic, functional, behavioral, and lected and the true diversity of the superorder historical. It is most remarkable—and very wel­ becomes evident, the number of pterosaur or­ come—that the volume is intended for a gener­ ders will certainly increase. al readership, even though it contains much of A minor point that seems to have escaped at­ technical interest. I consider it a tour de force tention is the spelling of the names Rhampho­ among popular paleontoiogjcal publications rhvnchoidia and Pterodactyloidia. These have and a splendid entry into the pterosaur litera­ invariably been spelled with the ending -oidea; ture. Except for adding the sharovipterygjans but this ending is reserved for superfamilies, ac­ and desynonymizing a few genera commonly sy- cording to the ICZN (1985). So I have slightly nonymized with others, my classification fol­ changed the ending to -oidia, which is appro­ lows the one used therein and in Wellnhofer's priate to both subordinal and ordinal levels. (1976) earlier monograph. Wellnhofer (1991) tabulates the numerous differences between the Rhamphorhvnchoidia Order Sharoviptervgia and the Pterodactyloidia, and I follow his classi­ The tail-gliding reptile Sharovipteryx was fication here. Among other things, the rham- morphologically so different from other archo­ phorhynchoids had jaws with numerous large saurs that it clearly requires a new order, Sha­ teeth; separate narial and antorbital openings; roviptervgia. Where to place this order within a short metacarpus; a backwardly directed oc­ (or outside) the Archosauria is moot, but inas­ cipital condyle (so that the skull was more or much as Sharovipteryx seems anatomically clos­ less in line with the neck); a long pedal digit V; est to the pterosaurs, I have tentatively classi­ and (usually) a long tail. Because the rhampho- fied the order Sharoviptervgia within the super- rhynchoids are regarded as ancestral to the lat­ order Pterosauria. er pterodactyloids, possibly through the Anuro- The problematic small archosaur Sclero- gnathidae, a family of short-tailed rhampho- mochlus has been suggested as related to ptero­ rhynchoids, the Rhamphorhvnchoidia is listed saur ancestry (Huene, 1914). In its relative as a paraorder. skull and limb proportions—very large skull rel­

Parainfraclass Archosauria Cope, 1869 57 Pterosaur Phylogeny Order Pterodactyloidia existed. Rhamphorhynchoids were fliers whose Pterosaurs in this order were characterized aerodynamic stability was abetted to some ex­ by jaws with fine teeth, few teeth, or none at tent by their tails. Pterodactyloids, lacking tails, all; nares and antorbital fenestrae merged into must were unstable fliers, in the sense that they a single opening; a long metacarpus; a down­ had to adjust their flight constantly by mus­ wardly directed occipital condyle (so that the cular effort. They were thus more maneuvera- skull was held at an angle to the neck); a re­ ble and efficient fliers than rhamphorhyn­ duced pedal digit V; and a short tail. Whereas choids, which may have aided the dramatic in­ rhamphorhynchoids remained relatively small, crease in size within the group. some pterodactyloids grew to spectacular siz­ es—the largest-known flying animals that ever

Pterosaur Phytogeny 58 Mesozoic Meanderings #2 Superorden Pterosauria Kaup, 1834

Census: 3 orders, 17 families, 59 genera (9 doubtful), 122 species (36 doubtful)

Order: Sharovipterygia nov. Census: 1 family, 2 genera, 2 species S. taylori Woodward, 1907 (Type) Family: SCLEROMOCHUOAE von Huene, 1914 Genus: Sharovipteryx Cowen, 1981 = Podopterix Ivakbnenko, 1978 [sic] Census: 2 genera, 2 species = Podopteryx Sharov, 1971/Selys- Longchamps, 1871 = Podopterygidae Sharov, 1971 S. mirabilis (Sharov, 1971) (Type) = Sharovipterygidae Tatarinov, 1989 = Podopteryx mirabilis Sharov, 1971 Genus: Sciervmochius Woodward, 1907 = Podopterix mirabilis Ivakhnenko, 1978 = Schlermochlus Glut, 1972 [sic] [sic] = Sclermochlus Glut, 1972 [sic]

Paraorden Rhamphorhynchoidia Plieninger, 1901 Census: 4 families, 18 genera (2 doubtful), 29 species (5 doubtful) Genus: Owen, 1859 Family: EUDIMORPHODONT1DAE D. macronyx (Buckland, 1829) (Type) Wellnhofer, 1978 = Pterodactylus macronyx Buckland, 1829 = macronyx (Buckland, Census: 1 genus, 1 species 1829) Genus: Zambelli, 1973 = Pterodactylus marderi Owen, 1874 E. ranzii Zambelli, 1973 (Type) [nomen dubium] Genus: Peteinosaurus Wild, 1978 P. zambellii Wild, 1978 (Type) Family: DIMORPHODONTIDAE Seeley, 1870 Genus: [To be described from the Dockum For­ mation of Texas; S. Chatterjee, pers. comm.] Census: 2 genera, 2 species

= Dimorphodontinae Hooley, 1913

Parainfraclass Archosauria Cope, 1869 59 Pterosauria Kaup, 1834 = Dimorphodon banthensis (Theodori, Family: ANUROGNATHIDAE 1830) Nopcsa, 1928 = Pterodactylus banthensis (Theodori, 1830) Census: 2 genera, 2 species = Rhamphorhynchus banthensis (Theo­ Genus: Anurognathus Doderlein, 1923 dori, 1830) = Anuroganthus Young, 1964 [sic] = Pterodactylus macronyx von Meyer, 1831 A. ammoni Doderlein, 1923 (Type) non Buckland, 1829 [nomen dubium] = Rhamphorhynchus macronyx (von Genus: Riabinin, 1948 Meyer, 1831) [nomen dubium] B. volans Riabinin, 1948 (Type) = Pterodactylus goldfussi Theodori, 1848 [nomen dubium] = Rhamphorhynchus goldfussi (Theodori, Family: RHAMPHORHYNCHIDAE 1848) [nomen dubium] Seeley, 1870 D. mistelgauensis Wild, 1971

Census: 12 genera (2 doubtful), Genus: Nesodactylus Colbert, 1969 23 species (5 doubtful) = Nesodon Jensen & Ostrom, 1977/Owen, 1840 [sic] = Campylognathoidinae Kuhn, 1967 N. hesperius Colbert, 1969 (Type) = Parapsicephalinae Kuhn, 1967 = Nesodon hesparius Jensen & Ostrom, = Rhamphorhynchinae Nopcsa, 1928 1977 [sic] = Scaphognathidae Hooley, 1913 Genus: Odontorhynchus Stolley, 1936 [nomen = Scaphognathinae Hooley, 1913 dubium] Genus: Angustinariptems He, Yan & Su, 1983 O. aculeatus Stolley, 1936 (Type) = Angustinarhiptems Dong, 1987 [sic] Genus: Parapsicephalus Arthaber, 1918 A. longicephalus He, Yan & Su, 1983 (Type) = Parapsicethalus Romer, 1966 [sic] = Angustinarhiptems congicephalus Dong, P. purdoni (Newton, 1888) (Type) 1987 [sic] = purdoni Newton, 1888 Genus: Campylognathoides Strand, 1928 Genus: Wild, 1983 = Camptyognathus Romer, 1966 [sic] P. buffarinii Wild, 1983 (Type) = Campylognathus Plieninger, 1894/Reuter, 1890 Genus: Rhamphocephalus Seeley, 1880 [nomen = Compylognathus Coombs, 1972 [sic] dubium] C. liasicus (Quenstedt, 1858) = Dolichorhamphus Seeley, 1885 = Pterodactylus liasicus Quenstedt, 1858 = Dolichorhampus Romer, 1966 [sic] = Campylognathus liasicus (Quenstedt, = Rhampocephalus Romer, 1966 [sic] 1858) R. bucklandi (von Meyer, 1832) (Type) C. ntteli (Plieninger, 1894) (Type) = Pterodactylus bucklandi von Meyer, = Campylognathus zitteli Plieninger, 1894 1832 [nomen dubium] C. indicus Jain, 1974 = Rhamphorhynchus bucklandi (von Meyer, 1832) [nomen dubium] Genus: Comodactylus Gallon, 1981 = Pterodactylus duncani Owen, 1874 C. ostromi Gallon, 1981 (Type) [nomen dubium] Genus: Wagner, 1860 - Pterodactylus kiddii Owen, 1874 [nomen D. banthensis (Theodori, 1830) (Type) dubium] = Omithocephalus banthensis Theodori, ?R. depressirostris (Huxley, 1859) [nomen 1830 dubium]

Pterosauria Kaup, 1834 60 Mesozoic Meanderings #2 = Rhamphorhynchus depressirostris Hux­ = Omithocephalus gemmingi (von Meyer, ley, 1859 [nomen dubium] 1846) = Pterodactylus aclandi Owen, 1874 = Pterodactylus lavateri von Meyer, 1838 [nomen dubium] [nomen dubium] ?R. prestwichi Seeley, 1880 [nomen dubium] = Omithopterus lavateri (von Meyer, 1838) = Dolichorhamphus prestwichi (Seeley, [nomen dubium] 1880) [nomen dubium] R. jessoni Lydekker, 1890 [nomen dubium] R. longiceps Woodward, 1902 Genus: Rhamphorhynchus von Meyer, 1846 = Omithocephalus giganteus Oken, 1819 = Omithopterus von Meyer, 1846 [nomen [nomen dubium] dubium] = Pterodactylus giganteus (Oken, 1819) = Pteromonodactylus Teriaev, 1967 [nomen dubium] = Ramphorhynchus von Meyer, 1847 [sic] = Pterodactylus grandis Cuvier, 1824 = Rhamphorhynchys Rao & Shah, 1982? [nomen dubium] [sic] = Omithocephalus grandis (Cuvier, 1824) R. muensteri (Goldfuss, 1831) = Omithocephalus muensteri Goldfuss, [nomen dubium] = Rhamphorhynchus grandis (Cuvier, 1831 1824) [nomen dubium] = Omithocephalus munsteri Goldfuss, = Pterodactylus secundarius von Meyer, 1831* 1843 [nomen dubium; juvenile?] = Pterodactylus muensteri (Goldfuss, 1831) = Omithocephalus secundarius (von = Pterodactylus munsteri (Goldfuss, 1831)* Meyer, 1843) [nomen dubium; juvenile?] = Rhamphorhynchus suevicus O. Fraas, = Rhamphorhynchus kokeni Plieninger, 1855 [nomen dubium] 1907 = Pterodactylus hirundinaceus Wagner, ?R. tendagurensis Reck, 1931 1857 [nomen dubium] R. intermedins Koh, 1937 = Rhamphorhynchus hirundinaceus (Wag­ [New large species to be described; ner, 1857) [nomen dubium] Wellnhofer, 1991: 151] = Rhamphorhynchus curtimanus Wagner, 1858 Genus: Scaphognathus Wagner, 1861 = Rhamphorhynchus longimanus Wagner, = Brachytrachelus Giebel, 1850 [nomen 1858 oblitum] = Rhamphorhynchus meyeri Owen, 1870 = Pachyramphus Romer, 1966 [sic] = Rhamphorhynchus phyllurus Marsh, 1882 = Pachyrhamphus Fitzinger, 1843 [nomen = Pteromonodactylus phyllurus (Marsh, oblitum] 1882) - Pycnorhamphus Zittel, 1882 [sic] = Rhamphorhynchus megadactylus von S. crassirostris (Goldfuss, 1831) (Type) Koenigswald, 1931 = Pterodactylus crassirostris Goldfuss, 1831 = Rhamphorhynchus carnegiei Koh, 1937 = Brachytrachelus crassirostris (Goldfuss, R. longicauaus (Miinster, 1839) (Type) 1831) = Pterodactylus longicauaus Miinster, 1839 = Omithocephalus crassirostris (Goldfuss, = Odontorhynchus longicauaus (Miinster, 1831) 1839) = Pachyrhamphus crassirostris (Goldfuss, = Omithocephalus longicauaus (Miinster, 1831) 1839) = Rhamphorhynchus crassirostris (Gold­ = Rhamphorhynchus longicaudatus von fuss, 1831) Amnion, 1884 [sic] Genus: Sordes Sharov, 1971 R. gemmingi (von Meyer, 1846) = Sordus Bakker, 1975 [sic] = Pterodactylus gemmingi von Meyer, 1846 S. pilosus Sharov, 1971 (Type)

Parainfraclass Archosauria Cope, 1869 61 Pterosauria Kaup, 1834 Genus: [To be described from Cene, near Ber­ RHAMPHORHYNCHOIDIA incertae sedis gamo, Italy, Fraser & Unwin, 1990] Census: 1 genus, 1 species Genus: [To be described from southern Austria; Fraser & Unwin, 1990] Genus: Rhamphinion Padian, 1984 = Rhamphion Fraser & Unwin, 1990 [sic] Genus: [To be described from the Triassic of R. jenkinsi Padian, 1984 (Type) Kalgary, western Texas; Murry, 1986]

Orden Pterodactyloidia Plieninger, 1901 Census: 12 families, 39 genera (7 doubtful), 91 species (31 doubtful) Genus: Dermodactylus Marsh, 1881 [nomen Family: PTERODACTYUDAE dubium] Bonaparte, 1838 = Dermodactylus Brown, 1943 [sic] D. montanus (Marsh, 1878) (Type) Census: 6 genera (1 doubtful), = Pterodactyius montanus Marsh, 1878 22 species (14 doubtful) [nomen dubium] = Gallodactylinae Fabre, 1981 Genus: Diopecephalus Seeley, 1871 = Ornithocephalidae Hay, 1902 D. longicollum (von Meyer, 1854) Seeley, = Ptenodraconinae Hooley, 1913 1871 (Type) = Pterodactylae Bonaparte, 1838 = Pterodactyius longicollum von Meyer, = Pterodactyl! von Meyer, 1830 1854 = Pterodactylia Blainville, 1835 = Gallodactylus longicollum (von Meyer, = Pterodactylina Bonaparte, 1838 1854) Fabre, 1974 = Pterodactylinae Williston, 1892 = Pterodactyius longipes Munster, 1836 Genus: Cycnorhamphus Seeley, 1870 [nomen oblitum] = Cygnorhamphus Seeley, 1870 [sic] = Omithocephalus longipes (Munster, = Cynorhamphus Romer, 1966 [sic] 1836) [nomen oblitum] C. suevicus (Quenstedt, 1855) Seeley, 1870 — Pterodactyius (Omithocephalus) vul- (Type) turinus Wagner, 1857 = Pterodactyius suevicus Quenstedt, 1855 = Pterodactyius vulturinus (Wagner, 1857) non Oken, 1825 = Omithocephalus vulturinus (Wagner, = Gallodactylus suevicus (Quenstedt, 1857) 1855) Fabre, 1974 = Pterodactyius longicollis von Meyer, = Pterodactyius wuerttembergicus Quen­ 1858 [«c] stedt, 1854 [nomen nudum] = Pterodactyius suevicus O. Fraas, 1878 = Pterodactyius wiirttembergicus Quen­ non Oken, 1825 stedt, 1854 [nomen nudum]* = Cycnorhamphus fraasi Seeley, 1901 = Pterodactyius eurychirus Wagner, 1957 = Pterodactyius fraasi (Seeley, 1901) = Pterodactyius (Omithocephalus) Genus: Gallodactylus Fabre, 1974 eurychirus (Wagner, 1857) G. canjuersensis Fabre, 1974 (Type) = Omithocephalus eurychirus (Wagner, 1857) Genus: Herbstosaurus Casamiquela, 1974 = Pterodactyius suevicus eurychirus Wag­ H. pigmaeus Casamiquela, 1974 (Type) ner, 1858 = Pterodactyius wurtembergicus Fabre, 1981 [sic]

Pterosauria Kaup, 1834 62 Mesozoic Meanderings #2 Genus: Pterodactylus Rafinesque, 1815 = Pterodactylus nettecephaloides Ritgen, = Macrotrachelus Giebel, 1850 1826 [nomen oblitium] = Omithocephalus Sommering, 1812 — Omithocephalus redenbacheri Wagner, [nomen oblitum] 1851 [nomen oblitium] = Perodactyhis Plieninger, 1929 [sic] = Pterodactylus redenbacheri (Wagner, = Ptenodracon Lydekker, 1888 1851) [nomen oblitium] = Pterodactyle Cuvier, 1809 [nomen oblitum] - Pterodactylus pulchellus von Meyer, 1861 = Pterodracon Lydekker, 1888 [sic] = Pterodactylus elegans Rikovsky, 1925 = Pterotherium Fischer, 1813 [nomen non Wagner, 1861 oblitum] ?P. propinquus Wagner, 1857 [nomen P. antiquus (Sommering, 1812) (Type) dubium] = Omithocephalus antiquus Sommering, = Omithocephalus propinquus (Wagner, 1812 1857) [nomen dubium] = Omithocephalus brevirostris Sommering, ?P. primus Deffner & O. Fraas, 1859 [nomen 1817 (juvenile) dubium] = Ptenodracon brevirostris (Sommering, ?P. cirinensis von Meyer, 1860 [nomen 1817) (juvenile) dubium] =Pterodactylus brevirostris (Sommering, = Pterodactylus cerinensis Lortet, 1892 [sic] 1817) (juvenile) ?P. grandipelvis von Meyer, 1860 [nomen = Pterodactylus longirostris Cuvier, 1819 dubium] = Macrotrachelus longirostris (Cuvier, 1819) P. elegans Wagner, 1861 = Omithocephalus longirostris (Cuvier, ?P. hopkinsi Seeley, 1864 [nomen nudum] 1819) ?P. macrurus Seeley, 1869 [nomen dubium] - Pterodactylus suevicus Oken, 1825 ?P. nobilis Owen, 1869 [nomen dubium] [nomen dubium] = Omithocheirus nobilis (Owen, 1869) = Pterodactylus crocodilocephaloides Rit- [nomen dubium] gen, 1829 [nomen dubium] = Omithochirus nobilis (Owen, 1869) = Pterodactylus spectabilis von Meyer, 1861 [nomen dubium] P. kochi (Wagner, 1837) ?P. suprajurensis Sauvage, 1873 [nomen = Omithocephalus kochii Wagner, 1837 dubium] = Diopecephalus kochi (Wagner, 1837) = Rhamphorhynchus suprajurensis = Pterodactylus meyeri Miinster, 1842 (Sauvage, 1873) [nomen dubium] (juvenile) ?P. manseli Owen, 1874 [nomen dubium] = Omithocephalus meyeri (Miinster, 1842) = Rhamphorhynchus manseli (Owen, (juvenile) 1874) [nomen dubium] = Pterodactylus scolopaciceps von Meyer, ?P. playdelli Owen, 1874 [nomen dubium] 1850 ?P. amingi Reck, 1931 [nomen dubium] = Rhamphorhynchus scolopaciceps (von ?P. maximus Reck, 1931 [nomen dubium] Meyer, 1858) = Pterodactylus elegans Broili, 1925 non Wagner, 1861 Family: GERMANODACTYLIDAE = Pterodactylus westmani Wiman, 1927 Young, 1964 = Pterodactylus cormoranus Doderlein, 1929 Census: 1 genus, 2 species = Pterodactylus elegans Edinger, 1941 non Wagner, 1861 Genus: Young, 1964 P. omis Giebel, 1847 [nomen dubium] = Germodactylus Wellnhofer, 1980 [sic] P. gracilis Theodori, 1852 [nomen dubium] G. rhamphastinus (Wagner, 1851) P. micronyx von Meyer, 1856 = Omithocephalus rhamphastinus Wagner, 1851

Parainf raclass Archosauria Cope, 1869 63 Pterosauria Kaup, 1834 = Diopecephalus rhamphastinus (Wagner, Family: PTERODAUSTRIDAE 1851) Bonaparte, 1971 = Pterodactylus rhamphastinus (Wagner, 1851) Census: 1 genus, 1 species = Pterodactylus medius Munster, 1831 = Pterodactylus intermedius Goldfuss, = Pterodaustriidae Bonaparte, 1971* 1831 [sic] = Pterodactylus dubius Munster, 1832 Genus: Bonaparte, 1969 = Omithocephalus dubius (Munster, 1832) P. guinazui Bonaparte, 1969 (Type) = Pterodactylus ramphatilus Weigelt, 1927 = Pterodaustro guinazui Bonaparte, 1969* [sic] = Germanodactylus ramphatilus Weigelt vide Schaefer, 1989 [sic] Family: DSUNGARIPTERIDAE G cristatus (Wiman, 1925) (Type) Young,1964 = Pterodactylus cristatus Wiman, 1925 = Pterodactylus kochi Plieninger, 1901 Census: 4 genera, 5 species (1 doubtful) (err. "Wagler, 1837") non Wagner, 1837 = Germanodactylus kochi (Plieninger, Genus: Young, 1964 1901) D. weii Young, 1964 (Type) = Germodactylus cristatus Wellnhofer, ?D. brancai (Reck, 1931) [nomen dubium] 1980 [sic] = Pterodactylus brancai Reck, 1931 [nomen dubium] Genus: Noripterus Young, 1973 Family: CTENOCHASMAT1DAE N. complicidens Young, 1973 (Type) Nopcsa, 1928 Genus: Phobetor Bakhurina, 1986 Census: 3 genera, 5 species = Fabeter Ivakhnenko & Korabelnikov, 1987 [sic] Genus: von Meyer, 1852 P. parvus (Bakhurina, 1982) (Type) C. roemeri von Meyer, 1852 (Type) = Dsungaripterus parvus Bakhurina, 1982 C. gracile Oppel, 1862 = Fabeter parvus Ivakhnenko & Korabel­ C. porocristatum de Buisonje, 1981 nikov, 1987 [sic] - Ctenochasma porocristata de Buisonje, NOTE: The above genus was named with­ 1981* out formal description in a review article (Priro- NOTE: Genera ending in -chasma are neu­ da 1986(1): 27-36), but it is treated as valid by ter, not feminine, and so take neuter adjectival Wellnhofer (1991). A recently published anony­ specific names. Hence the spelling change to mous museum pamphlet on Mongolian fossils C. porocristatum. (in Russian) illustrates a Phobetor skull and re­ fers it to the Ornithocheiridae. Genus: von Meyer, 1834 G. subulatus von Meyer, 1834 (Type) Genus: Puntanipterus Bonaparte & Sanchez, = Crocodilus multidens Munster, 1832 1974 = Gnathosaurus multidens (Munster, 1832) = Puntaniptero [Anonymous] 1976 [sic] = Gavialis priscus Quenstedt, 1855 = Putanipterus Carroll, 1987 [sic] [nomen dubium] P. globosus Bonaparte & Sanchez, 1974 (Type) Genus: Dong, 1982 = Huanhopterus Dong, 1987 [sic] H. quingyangensis Dong, 1982 (Type) = Huanhopterus qinyangensis Dong, 1987 [sic]

Pterosauria Kaup, 1834 64 Mesozoic Meanderinqs #2 = Pterodactylus diomedius (Owen, 1846) Family: ORNITHOCHEIRIDAE = Pterodactylus conirostris Owen, 1850 (Seeley, 1870) [nomen dubium] O. giganteus (Bowerbank, 1846) [nomen Census: 5 genera, 25 species (8 doubtful) dubium] = Omithocheirae Seeley, 1870 = Pterodactylus giganteus Bowerbank, 1846 = Ornithocheirinae Plieninger, 1907 non Oken, 1819 [nomen dubium] = Lonchodectes giganteus (Bowerbank, Genus: Araripesaums Price, 1971 1846) [nomen dubium] A. castilhoi Price, 1971 (Type) = Omithochirus giganteus (Bowerbank, Genus: Kellner, 1984 1846) [nomen dubium] B. araripensis Kellner, 1984 (Type) = Omithodesmus giganteus (Bowerbank, = Brasileodactylus araripendis Kellner, 1846) [nomen dubium] 1989 [sic] O. compressirostris (Owen, 1851) (Type) = Pterodactylus compressirostris Owen, Genus: Leonardi & Borgoma- 1851 nero, 1983 = Lonchodectes compressirostris (Owen, C atrox Leonardi & Borgomanero, 1983 1851) (Type) = Omithocheims compressiformis Gaal, NOTE: This genus may require placement 1926 [sic] in its own family (P. Wellnhofer, pers. comm. O. cuvieri (Bowerbank, 1851) at 1989 SVP annual meeting). = Pterodactylus cuvieri Bowerbank, 1851 Genus: Omithocheims Seeley, 1869 = cuvieri (Bowerbank, = Cimoliomis Owen, 1846 1851) = Cretomis Fritsch, 1880 [nomen dubium] = Omithochirus cuvieri (Bowerbank, 1851) = Lithosteomis Gervais, 1844 [nomen = Ptenodactylus cuvieri (Bowerbank, 1851) nudum] lO.ftttoni (Owen, 1859) = Lonchodectes Hooley, 1914 = Pterodactylus fittoni Owen, 1859 = Omithochirus Lydekker, 1888/Cope, 1872 = Omithochirus fittoni (Owen, 1859) [sic] = Ptenodactylus fittoni (Owen, 1859) = Osteomis Gervais, 1844 [nomen nudum] ?0. sedgwicki (Owen, 1859) = Palaeomis Mantell, 1835/Vigors, 1825 = Pterodactylus sedgwicki Owen, 1859 = Coloborhynchus sedgwicki (Owen, 1859) = Ptenodactylus Seeley, 1869 = Omithochirus sedgwicki (Owen, 1859) ?0. clifti (Mantell, 1835) = Ptenodactylus sedgwicki (Owen, 1859) = Palaeomis clifti Mantell, 1835 O. machaerorhynchus (Seeley, 1864) [nomen = Omithochirus clifti (Mantell, 1835) dubium] = Pterodactylus clifti (Mantell, 1835) = Pterodactylus machaerorhynchus Seeley, = Osteomis ardeaceus Gervais, 1844 [nomen nudum] 1864 [nomen dubium] — Lithosteomis ardeaceus (Gervais, 1844) = Lonchodectes machaerorhynchus [nomen nudum] (Seeley, 1864) [nomen dubium] = Pterodactylus silvestris Owen, 1845 = Ptenodactylus machaerorhynchus = Pterodactylus sylvestris Plieninger, 1929 (Seeley, 1864) [nomen dubium] [sic] = Omithocheims machaeorhynchus ?0. diomedeus (Owen, 1844) Wellnhofer, 1978 [sic] = Osteomis diomedeus Owen, 1844 O. oweni (Seeley, 1864) [nomen nudum] = Cimoliomis diomedius Owen, 1846 = Pterodactylus oweni Seeley, 1864 [nomen = Omithocheims diomedius (Owen, 1846) nudum] = Omithochirus diomedius (Owen, 1846) = Lonchodectes oweni (Seeley, 1864) [nomen nudum]

Parainfraclass Archosauria Cope, 1869 65 Pterosauria Kaup, 1834 = Ptenodactylus oweni (Seeley, 1864) = Lonchodectes tenuirostris (Seeley, 1869) [nomen nudum] [nomen nudum] O. brachyrhinus (Seeley, 1869) [nomen ?0. curtus (Seeley, 1870) [nomen dubium] nudum] = Pterodactylus curtus Seeley, 1870 = Ptenodactylus brachyrhinus Seeley, 1869 [nomen dubium] [nomen nudum] = Omithochirus curtus (Seeley, 1870) O. colorhinus (Seeley, 1869) [nomen nudum] [nomen dubium] = Ptenodactylus colorhinus Seeley, 1869 O. huxleyi Seeley, 1870 [nomen dubium] [nomen nudum] O. xyphorhynchus Seeley, 1870 [nomen O. dentatus (Seeley, 1869) [nomen nudum] dubium] = Ptenodactylus dentatus Seeley, 1869 = Omithochirus xyphorhynchus (Seeley, [nomen nudum] 1870) [nomen dubium] O. enchorhynchus (Seeley, 1869) [nomen O. daviesii (Owen, 1874) nudum] = Pterodactylus daviesii Owen, 1874 = Ptenodactylus enchorhynchus Seeley, = Lonchodectes daviesii (Owen, 1874) 1869 [nomen nudum] = Omithochirus daviesii (Owen, 1874) O. macrorhinus (Seeley, 1869) [nomen = Omithocheirus denticulatus Seeley, 1870 nudum] [nomen dubium] = Ptenodactylus macrorhinus Seeley, 1869 = Omithochirus denticulatus (Seeley, [nomen nudum] 1870) [nomen dubium] O. microdon (Seeley, 1869) [nomen dubium] O. sagittirostris (Owen, 1874) [nomen = Ptenodactylus microdon Seeley, 1869 dubium] [nomen dubium] = Pterodactylus sagittirostris Owen, 1874 = Lonchodectes microdon (Seeley, 1869) [nomen dubium] [nomen dubium] = Lonchodectes sagittirostris (Owen, 1874) O. nasutus (Seeley, 1869) [nomen nudum] [nomen dubium] = Ptenodactylus nasutus Seeley, 1869 = Omithodesmus sagittirostris (Owen, [nomen nudum] 1874) [nomen dubium] O. oxyrhinus (Seeley, 1869) [nomen nudum] O. hlavatschi (Fritsch, 1880) [nomen dubium] = Ptenodactylus oxyrhinus Seeley, 1869 = Cretomis hlavatschi Fritsch, 1880 [nomen nudum] [nomen dubium] = Pterodactylus oxyrhinus (Seeley, 1869) = Omithochirus hlavatschi (Fritsch, 1880) [nomen nudum] [nomen dubium] O. poiyodon (Seeley, 1869) [nomen nudum] = Omithocheirus hlavaci Fritsch, 1905 [sic] = Ptenodactylus poiyodon Seeley, 1869 O. bunzeli Seeley, 1881 [nomen nudum] ?0. hilsensis Koken, 1883 [nomen dubium] O. scaphorhynchus (Seeley, 1869) [nomen O. wiedenrothi Wild, 1990 nudum] Genus: Santanadactylus de Buisonje, 1980 = Ptenodactylus scaphorhynchus Seeley, = Sandactylus Bowler, 1989 [sic] 1869 [nomen nudum] S. brasilensis de Buisonje, 1980 (Type) = Lonchodectes scaphorhynchus (Seeley, 5. araripensis Wellnhofer, 1985 1869) [nomen nudum] S. pricei Wellhofer, 1985 O. tenuirostris (Seeley, 1869) [nomen nudum] = Ptenodactylus tenuirostris Seeley, 1869 ?S. spbd Wellhofer, 1985 [nomen nudum] NOTE: Bennett, 1989 considers Santanadac­ tylus araripensis and S. pricei to be pteranodon- tids and S. spbd to be a dzungaripterid. Ben­ nett also notes that the type species may be based on a composite specimen: part pterano- dontid, part something else.

Pterosauria Kaup, 1834 66 Mesozoic Meanderings #2 = Ptenodactylus platystomus Seeley, 1869 Family: CRIORHYNCHIDAE [nomen nudum] Hooley, 1914 = Ambfydectes platystomus (Seeley, 1869) [nomen nudum] Census: 3 genera, 5 species (1 doubtful) - Omithocheirus platystomus (Seeley, Genus: Araripedactylus Wellnhofer, 1977 1869) [nomen nudum] A. dehmi Wellnhofer, 1977 (Type) = Omithochirus platystomus (Seeley, 1869) [nomen nudum] Genus: Giorhynchus Owen, 1874 C. reedi (Seeley, 1870) [nomen dubium] = Ambfydectes Hooley, 1914 [nomen nudum] = Omithocheirus reedi Seeley, 1870 = Coloborhynchus Owen, 1874 [nomen dubium] C simus (Owen, 1861) (Type) = Pterodactylus simus Owen, 1861 Genus: Wellnhofer, 1987 = Omithocheirus simus (Owen, 1861) T. mesembrinus Wellnhofer, 1987 (Type) = Pterodactylus woodwardi Owen, 1861 = mesembrinus (Wellnhofer, = Criorhynchus woodwardi (Owen, 1861) 1987) = Omithocheirus woodwardi (Owen, 1861) T. robustus Wellnhofer, 1987 = Ptenodactylus woodwardi (Owen, 1861) = Anhanguera robustus (Wellnhofer, 1987) = Omithocheirus carteri Seeley, 1869 NOTE: P. Wellnhofer (pers. comm. at 1989 [nomen nudum] SVP annual meeting) regards this genus as a = Criorhynchus carteri (Seeley, 1869) junior synonym of Araripedactylus. Kellner & [nomen nudum] Campos, 1989 regard it as a junior synonym of = Omithocheirus piatyrhinus Seeley, 1869 Anhanguera. It is best to keep this genus sepa­ [nomen nudum] rate until more Santana pterosaur material is described. = Criorhynchus piatyrhinus (Seeley, 1869) [nomen nudum] = Coloborhynchus clavirostris Owen, 1874 = Criorhynchus clavirostris (Owen, 1874) Family: ANHANGUERIDAE = Omithocheirus clavirostris (Owen, 1874) Campos & Kellner, 1985 C capito (Seeley, 1869) [nomen nudum] = Ptenodactylus capito Seeley, 1869 Census: 1 genus, 2 species [nomen nudum] Genus: Anhanguera Campos & Kellner, 1985 - Omithocheirus capito (Seeley, 1869) = Anghanguera Wellnhofer, 1988 [sic] [nomen nudum] — Anhanguera Campos vide Leonardi, 1984 C. crassidens (Seeley, 1869) [nomen nudum] [nomen nudum] = Ptenodactylus crassidens Seeley, 1869 A. blittersdorffi Campos & Kellner, 1985 [nomen nudum] = Ambfydectes crassidens (Seeley, 1869) (Type) A. santanae (Wellnhofer, 1985) [nomen nudum] = Araripesaurus santanae Wellnhofer, 1985 = Omithocheirus crassidens (Seeley, 1869) [nomen nudum] C. eurygnathus (Seeley, 1869) [nomen nudum] Family: TAPEJARIDAE Kellner, 1989 - Pterodactylus eurygnathus Seeley, 1869 [nomen nudum] - Ambfydectes eurygnathus (Seeley, 1869) Census: 2 genera, 2 species [nomen nudum] Genus: Tapejara Kellner, 1989 = Omithocheirus eurygnathus (Seeley, T. wellnhoferi Kellner, 1989 (Type) 1869) [nomen nudum] C. platystomus (Seeley, 1869) [nomen nudum]

Parainfraclass Archosauria Cope, 1869 67 Pterosauria Kaup, 1834 Genus: Keilner & Campos, 1988 NOTE: Apatomerus is probably not ptero- T. longicristatus Keilner & Campos, 1988 saurian and may be a (C. Bennett, pers. (Type) comm.; R. E. Molnar, pers. comm.). NOTE: A. Keilner (pers. comm. at 1989 Genus: Bogoliubovia Nessov & Borkin, 1989 SVP annual meeting) now believes this genus B. orientalis (Bogoliubov, 1914) (Type) may be an azhdarchid, based on comparison = Omithostoma orientate Bogoliubov, 1914 with undescribed skull material = Omithostoma orientalis Bogoliubov, at the Balcones Research Laboratory in Aus­ 1914* tin, Texas. = Pteranodon orientalis (Bogoliubov, 1914) NOTE: Genera ending in -stoma are neuter, not feminine, and so take neuter adjectival spe­ Family: NYCTOSAURIDAE cific names. Hence the spelling change to Omi­ Bennett, 1989 thostoma orientate. Census: 1 genus, 3 species Genus: Geostembergia Miller, 1978 [nomen novum ex subgenero] = Nyctosaurinae Plieninger, 1907 = Stembergia Miller, 1972/Jordan, 1925 (as Genus: Marsh, 1876 a subgenus of Pteranodon) = Nyctodactylus Marsh, 1881 G. stembergi (Harksen, 1966) n. comb. = Nytosaums Molnar, 1980 [sic] (Type) N. gracilis Marsh, 1876 (Type) = Pteranodon stembergi Harksen, 1966 = Nyctodactylus gracilis (Marsh, 1876) = Pteranodon (Stembergia) stembergi = Pteranodon gracilis (Marsh, 1876) (Harksen, 1966) = Pteranodon (Nyctosaurus) gracilis =» Pteranodon (Geostembergia) stembergi (Marsh, 1876) (Harksen, 1966) = Nyctosaurus leptodactylus Williston, 1903 G. walked (Miller, 1972) n. comb. JV. lamegoi Price, 1953 = Pteranodon (Stembergia) walkeri Miller, = Pteranodon (Nyctosaurus) lamegoi 1972 (Price, 1953) = Pteranodon walkeri (Miller, 1972) N. bonneri (Miller, 1972) = Pteranodon (Geostembergia) walkeri = Pteranodon (Nyctosaurus) bonneri (Miller, 1972) Miller, 1972 NOTE: Geostembergia walkeri may be a NOTE: See note for Pteranodon below. growth stage of G. stembergi. See also note for Pteranodon below. Genus: Omithostoma Seeley, 1870 [nomen dubi­ Family: PTERANODONTIDAE um] Marsh, 1876 O. seeleyi Lydekker, 1904 (Type)

Census: 5 genera (2 doubtful), Paragenus: Pteranodon Marsh, 1876 11 species (3 doubtful) = Omithochirus Cope, 1872 = Omithostoma Williston, 1893 non Seeley, = Ornrthostomatidae Williston, 1893 1870 = Pteranodontes Gadow, 1901 P. ingens (Marsh, 1872) = Pteranodontia Marsh, 1876 = Pterodactylus ingens Marsh, 1872 = Pteranodontinae Kuhn, 1967 = Omithostoma ingens (Marsh, 1872) = Pteranodon (Longicepia) ingens (Marsh, Genus: Apatomerus Williston, 1903 [nomen 1872) dubium] = Pteranodon (Pteranodon) ingens A. minis Williston, 1903 (Type) (Marsh, 1872) = Omithochirus umbrosus Cope, 1872

Pterosauria Kaup, 1834 68 Mesozoic Meanderings #2 = Pteranodon umbrosus (Cope, 1872) 1984) that belongs in its own family (Bennett, = Pterodoctylus umbrosus (Cope, 1872) 1989); Occidentalia is simply another junior syn­ = Pteranodon (Longicepia) marshi Miller, onym of Pteranodon (Wellnhofer, 1978); and 1972 Stembergia is preoccupied, necessitating a = Pteranodon (Pteranodon) marshi name change to Geostembergia (Miller, 1978). (Miller, 1972) Furthermore, the subgenus Geostembergia is = Pteranodon marshi (Miller, 1972) here separated from Pteranodon, because the P. occidentals (Marsh, 1872) shape of the cranial crest of the type skull dif­ = Pterodoctylus occidentalis Marsh, 1872 fers dramatically from those of other specimens = Pteranodon (Occidentalia) occidentalis referred to Pteranodon, the of the type (Marsh, 1872) skull is relatively longer than those of referred = Pterodoctylus oweni Marsh, 1871 non Pteranodon specimens, and the beak is curved Seeley, 1864 upward instead of being straight. Geostember­ = Omithochirus harpyia Cope, 1872 gia is, however, almost certainly descended = Omithocheirus harpyia (Cope, 1872) from a species of Pteranodon, which makes the = Pteranodon (Occidentalia) eatoni Miller, latter a paragenus. 1972 Padian (1984) and Bennett (1989) do not = Pteranodon eatoni (Miller, 1972) consider Pteranodon oregonensis to be a pteran- = Pteranodon oxydactylus McGinnis, 1982 odontid; Murry, Winkler & Jacobs (1991) refer [sic] the species to the Azdarchidae. P. velox (Marsh, 1872) Genus: [To be described from Colorado; may = Pterodoctylus velox Marsh, 1872 = Pteranodon comptus Marsh, 1876 be either a new genus or a new species of Pter­ P. longiceps Marsh, 1876 (Type) anodon; C. Bennett, R. Bakker, D. Weisham- = Pteranodon (Longicepia) longiceps pel, pers. comms.] (Marsh, 1876) = Pteranodon (Pteranodon) longiceps (Marsh, 1876) Family: AZHDARCHIDAE Padian, 1986 NOTE: The above species may be a junior synonym of Pteranodon ingens, which would Census: 4 genera (1 doubtful), make P. ingens the type species of the genus. 4 species (1 doubtful) P. nanus Marsh, 1881 = Azhdarchinae Nessov, January 1984 = Nyctosaurus nanus (Marsh, 1881) = Titanopterygiidae Padian, ?P. oregonensis Gilmore, 1928 December 1984 NOTE: This paragenus is organized accord­ ing to Wellnhofer (1978) and Schoch (1984). Genus: Arambourgiania Nessov & Borkin, 1989 Miller (1972) subdivided the genus into four = Titanopteryx Arambourg, 1959/Preoccu- subgenera: Longicepia Miller, 1972 (type spe­ pied cies Pteranodon longiceps Marsh, 1876), Occi­ A. philadelphiae (Arambourg, 1959) (Type) dentalia Miller, 1972 (type species Pteranodon = Titanopteryx philadelphiae Arambourg, (Occidentalia) eatoni Miller, 1972, based on a 1959 specimen originally referred to Pteranodon occi­ [New species to be described; Baird, 1986] dentalis Marsh, 1872 in Marsh, 1876), Stember- Genus: Azhdarcho Nessov, 1984 gia Miller, 1972 (type species Pteranodon Stern­ = Azhdarcho Nessov, 1982 [nomen nudum] berg Harksen, 1966), and Nyctosaurus Marsh, A. lancicollis Nessov, 1984 (Type) 1876 (type species Nyctosaurus gracilis Marsh, = Azhdarcho imparidens Nessov, 1982 1876). However, Longicepia is a junior synonym [nomen nudum] of Pteranodon itself, used as a subgenus, be­ cause it contains the type species; Nyctosaurus is a genus distinct from Pteranodon (Schoch,

Parainfraclass Archosauria Cope, 1869 69 Pterosauria Kaup, 1834 Genus: Doratorhynchus Seeley, 1875 [nomen L. prisca Marsh, 1881 (Type) dubium] = Loopteryx priscus Marsh, 1881 [nomen D. validus (Owen, 1870) (Type) dubium]* = Pterodactylus validus Owen, 1870 NOTE: The above genus was originally de­ [nomen dubium] scribed as avian, but it is "almost certainly a = Cycnorhamphus validus (Owen, 1870) pterosaur" (Brodkorb, 1978). This assignment [nomen dubium] has been confirmed by Ostrom, 1986. = Omithocheirus validus (Owen, 1870) Genus: Mesadactylus Jensen & Padian, 1989 [nomen dubium] [nomen dubium] = Omithochirus validus (Owen, 1870) M. omithosphyos Jensen & Padian, 1989 [nomen dubium] (Type) = Doratorhynchus valiaum Owen, 1891 [sic] Genus: Pricesaurus Martins Neto, 1986 [nomen dubium] Genus: Quetzalcoatlus Lawson, 1975 [nomen P. megalodon Martins Neto, 1986 (Type) nudum] Q. northropi Lawson, 1975 (Type) Genus: [To be described by S. Howse & An­ NOTE: Despite numerous popular accounts drew Milner] of this "largest known flying animal," this gen­ [Type species to be redescribed] us remains formally undescribed and is techni­ = Omithodesmus latidens Seeley, 1901 cally a nomen nudum. In view of their exceptio­ NOTE: The genus Omithodesmus, formerly nal nature and popular exposure, this genus classified as a pterosaur, is to be redescribed and its type species are included in this fami­ as a theropod dinosaur (SVP Bulletin #145: 43; ly's census. More than one species may be rep­ Wellnhofer, 1991), but the referred species O. resented in the referred material from Texas. latidens represents a .new family of "duck­ billed" pterosaurs. Because this species has a warped deitopectoral crest on the humerus, PTERODACTYLOIDIA incertae sedis however, Bennett (1989) considers it to be re­ lated to the Pteranodontidae. Census: 3 doubtful genera, 4 species (3 doubtful) Genus: Loopteryx Marsh, 1881 [nomen dubium]

Pterosauria Kaup, 1834 70 Mesozoic Meanderings #2 Dinosaur Phylogeny

N AUGUST 2, 1841, Sir , in the dinosaurs that reflects something of the ac­ Oan address to the British Association for cumulated knowledge of the past hundred the Advancement of Science (11th Meeting, years is long overdue. Plymouth), created the name Dinosauria to de­ Thus, as part of my reorganization of the ar- note "a distinct tribe or sub-order of Saurian chosaurs, I have made a number of changes to Reptiles." In the lengthy published version of the traditional classification of the dinosaurs. this report (Owen, 1842), the Dinosauria com­ Many of these are cosmetic, in the sense that prised just three genera of large fossil reptiles, the organization of the groups is not changed, all British: Megaiosaurus, Iguanodon, and Hylae- only their hierarchic levels within the Linnaean osaurus. taxonomy are. Other changes are more funda­ Forty-six years later, the number of genera mental, however, and in some cases proposed referable to the Dinosauria had increased by changes may at first sight seem to conflict with more than an order of magnitude. Dinosaurian the results of modern systematic studies. It is morphology had become much better known as the purpose of this section to justify my chang­ a result of discoveries in Europe and North es and to convince readers that the classifica­ America, and it was becoming clear that a sin­ tion presented here is at least broadly correct— gle reptilian order could not accommodate the and perhaps more useful than others previously entire range of dinosaurian diversity. Thus proposed. Harry Govier Seeley, in an address to the same Association (57th Meeting, Manchester, 1887), split the Dinosauria into two orders: Saurischia DEFINING DINOSAURS and Ornithischia (Seeley, 1888). Within a few decades, Seele/s dinosaur taxonomy supersed­ Dinosaurs are the best-known and most di­ ed classifications proposed by Cope (1870), verse of the archosaurs. Animals commonly Marsh (1895), Nopcsa (1915), and others, and called dinosaurs first appear in the fossil rec­ it has survived essentially unchanged to the ord early in the Late Triassic (Carnian). Even present. The dinosaurs became widely recog­ at this stage of dinosaur diversification, the nized as a diphyletic group, because the orders three major superorders — Theropodomorpha, Saurischia and Ornithischia were thought to Sauropodomorpha, and Ornithischia — are have descended independently from the order readily distinguishable (Sues, 1990; Gallon, Thecodontia. 1990; Weishampel & Witmer, 1990). Recent Now, more than a century after Seele/s ciadistic analyses of the dinosaurs, summarized work was published, the number of dinosaur by Benton (1990a), have indicated that the di­ genera has again grown by roughly an order of nosaurs plus the birds comprise a genuine magnitude. Seele/s classification is still used in clade within the clade Archosauria. This means most works, but as I noted earlier, it has be­ not only that all three dinosaur lineages were come clear to me that dinosaurs were too mor­ descended from a common ancestor, but also phologically diverse to be adequately classified that everyone would agree that this common an­ in only two orders. A revised classification of cestor was itself a dinosaur. This requirement of

Parairrfraclass Archosauria Cope, 1869 71 Dinosaur Phylogeny dinosaur is not often emphasized in a key feature of dinosaunan evolution. Origi­ dinosaur taxonomic analyses. nating as sprawling proterosuchian archosaurs Dinosaur monophyly is a matter of defini­ with primitive mesotarsal ankles, the dinosaurs tion. There is no doubt that within the clade evolved into fully erect animals with advanced Archosauria a smallest clade exists that com­ mesotarsal (AM) ankles. This adaptation made prises all the animals commonly called dino­ dinosaurs efficient foragers and runners capa­ saurs. By coincidence, this clade is congruent ble of outrunning predators with less-advanced to the smallest clade containing Owen's origi­ locomotor ability (such as ) and over­ nal three genera and the genus Cetiosaums. taking less-advanced prey. More than anything Owen described Cetiosaums—though not as a else, this is considered the reason for the suc­ dinosaur—the same year he proposed the term cess dinosaurs enjoyed throughout the Jurassic Dinosauria. So there are good historical as well and Cretaceous periods. as phyletic reasons for naming this particular Charig (1972) gave a very clear exposition of clade Dinosauria. Since, as noted earlier, this the evolution of erect stance in thecodontians. clade also includes the birds, I would defme Di­ The first stage is represented by the sprawling nosauria as a parataxon: the clade Dinosauria proterosuchians, with a primitive mesotarsal an­ minus the clade Aves. kle. The second stage is represented by the For reasons that follow, however, I believe semi-erect erythrosuchids and other thecodon­ that the parataxon Dinosauria includes animals tians with CN and CR ankles. Dinosaurs and that most dinosaurologists would hesitate to pterosaurs were the end products of this series, call dinosaurs: small, bipedal runners such as equipped with a fully erect stance and AM an­ ; arboreal climbers and gliders such kles. The major problem with this scenario, as as Megalancosaunts and Longisquama; birdlike Charig himself noted (1972: 152), is the difficul­ animals such as Protoavis and Archaeopteryr, ty of deriving the AM ankle from a CN/CR an­ and a wide range of other small, as-yet-undis­ kle. He considered this obstacle not insur­ covered forms with features transitional among mountable, but he also suggested that the dino- the dinosaunan and avian lineages. There is saurian ankle may have derived directly from also some chance that the clade Dinosauria in­ the primitive mesotarsal ankle via a small, light cludes the clade Pterosauria; if so, I would not "pseudosuchian, as yet unknown." hesitate to remove it, too, from the parataxon In the scenario proposed here, Chang's un­ Dinosauria. It seems to me that we are left known pseudosuchian is, naturally, a basithero- with two choices: either we call those unusual pod theropodomorph. A small, lightly built archosaurs dinosaurs, or we agree that the di­ form would not require the evolution of a com­ nosaurs were polyphyletic (Charig, 1982). plicated, weight-bearing CN/CR tarsus but In this work, I use the term "dinosaur" infor­ could evolve an erect gait and an AM ankle mally for any animal in the parataxon Dinosau­ directly from the primitively mesotarsal hind ria as just described. I do not intend to formal­ limb possessed by the earliest archosaurs. ize the parataxon, however, because so many Exactly how erect stance and the associated basal dinosaurs remain undiscovered that the AM ankle evolved among the dinosaurs re­ detailed relationships among the three major mains a matter of debate. Chatterjee (1985), dinosaunan subclades cannot be elucidated. In for example, has argued for a diphyletic origin a cladogram, the dinosaur node would appear of the AM ankle. Gauthier (1986a) and Benton as an unresolved trichotomy (at least). (1990a), on the other hand, supported the idea that the AM ankle developed from the CR an­ kle of the ornithosuchians by including Omitho- ORIGIN OF THE ERECT STANCE suchus close to the dinosaunan branch of their ciadograms. Bakker (1986: 450-451, 456), in Most workers (e.g., Charig, 1972, 1982; Bak- his own archosaur phylogeny, suggested that ker, 1986; Paul, 1988b; Benton, 1990a; and oth­ the ornithosuchians are best grouped with the ers) regard the trend toward an erect stance as CN-ankled thecodontians, away from the ptero-

Dinosaur Phylogeny 72 Mesozoic Meanderings #2 saurian and dinosaurian lineages. Although modification of the ankle, in which the calcane- Bakker did not disclose all of his reasons for uin acquired a large tuber for greater leverage, thinking so, he did cite several ornithosuchid would have been unnecessary in a semi-erect apomorphies that appear in no other archosaur animal that remained small and light. The pes lineage. The AM-ankled dinosaurs are depict­ would have remained plantigrade as the animal ed by Bakker as a lineage independent of the walked, and muscular power alone would have CN/CR-ankled thecodontians. been sufficient to maintain its semi-erect pos­ The first question that needs to be ad­ ture; the structure of the ankle was simply not dressed is, Why did the semi-erect and fully particularly important. (At this point, I must erect stances evolve at all? Most extant rep­ ask the reader to take this on faith, because not tiles, even large ones—those that have legs and a single fully terrestrial proterosuchian has yet use them, that is—walk in a sprawling stance been identified in the fossil record.) and never evolved an erect stance. Crocodilians Reptiles with three-chambered hearts have are a special case: As noted earlier, they did grown quite large (e.g., Varanus komodoensis, evolve fully erect forms but later adopted a ri­ tortoises) without having evolved the kinds of parian lifestyle and reverted to a semi-erect weight-related structural modifications to their stance. They retain only vestiges of their former ankles seen in the semi-erect and fully erect ar­ locomotor ability. chosaurs. Without the improved aerobic meta­ I believe the answer to this question lies in bolism afforded by a four-chambered heart, the development of the elevated aerobic capaci­ however, reptiles with three-chambered hearts ty afforded by a four-chambered heart (Regal could only retain the sprawling posture and sit- & Gans, 1980). The non-mammalian four-cham­ and-wait predation strategy of their smaller rel­ bered heart is thought to be a synapomorphy atives. The kinds of structural modifications to uniting extant crocodilians and birds, and if so, their limbs required by an improved stance it must have arisen in a common ancestor of were unnecessary. I suggest that the semi- and both groups. Only one group is available in fully erect stance in amniotes is well correlated which to classify this ancestor, assuming it was with the presence of a four-chambered heart an archosaur of some kind and not an earlier and an elevated aerobic capacity, rather than predecessor, and that is the Proterosuchia. the more complicated physiologies associated Extant non-archosaurian reptiles possess with endothermy suggested by Ostrom (1980) three-chambered hearts, which are less effi­ and Bakker (1980). cient at blood oxygenation. It is likely that this The absence of proterosuchians and early is the principal reason that most extant reptiles theropodomorphs, sauropodomrphs, and orni- engage in sit-and-wait behavioral patterns. thischians from the fossil record makes it diffi­ With the evolution of the four-chambered cult to track the evolution of the AM ankle. It heart, archosaurs would have possessed the me­ must be remembered that this occurred in tabolic equipment for sustained foraging activi­ small, lightweight, fully terrestrial, plantigrade ty and escape from pursuit by preda­ proterosuchians in which the tarsal structure tors. (As mammalian ancestors, therapsids was subordinate to the orientation of the fe­ were undoubtedly equipped with their own ver­ mur, epipodials, and pes. Only among such ani­ sion of a four-chambered heart by then.) The mals would the ankle have retained so much of development of the four-chambered heart prob­ its original mesotarsal condition. Such animals, ably slightly preceded the improvements in unfortunately, would also have been among the stance among the archosaurs, but it is equally least likely to be preserved in the fossil record. possible that the circulatory and locomotor im­ The two epipodial bones in the limbs of the provements evolved in parallel. sprawling proterosuchians were surely well In this work, I take the position that the CN adapted to transmitting the horizontal motion and CR ankles evolved as a result of the in­ of the propodial bones to the plantigrade man- creased size and weight that characterized the us and pes. In particular, the long axes of proxi­ more advanced thecodontians. This kind of mal and distal ends of the were roughly

Parainfraclass Archosauria Cope, 1869 73 Dinosaur Phylogeny parallel, since in a relaxed position the planti­ been as pronounced as they were in the hind grade pes extended roughly parallel to the hori­ limb. Once the hind limb had attained a cer­ zontal , outward from the body. As the fe­ tain degree of semi-erectitude, the forelimb mur straightened and became more vertical, would have been freer to assume non-locomo- the pes was required to rotate less and less. tor functions, such as grasping and climbing, as The long axis of the proximal end of the tibia in extant rats and squirrels. Even many would have remained aligned in the direction are excellent climbers, so it is not at all difficult tangential to the limb's motion, but the long to imagine the trees of the Late Permian and axis of its distal end would have become pro­ Early Triassic replete with many species of gressively more perpendicular to the direction sprawling and semi-erect arboreal archosaurs, of the animal's motion. This gave the tibia the in addition to the ground-dwelling forms. torsion characteristic of dinosaurs and birds. Those archosaurs that attained a suitable de­ The "tibia-twist" was not nearly as evident in gree of semi-erectitude should no longer be pterosaurs as in dinosaurs, because the ptero­ considered proterosuchians; they would have saur lineage diverged from the dinosaur line­ been the earliest members of the dinosaur and age before the fully erect stance evolved. pterosaur clades. Paralleling the tibial change, the femoral head, which inserted into the acetabulum hori­ zontally and loosely in sprawling forms, devel­ EARLY DINOSAURS oped a neck that allowed the femur to be held more firmly at an angle from the horizontal. It is not known when or in what order the This eventually became a right angle in fully three dinosaurian lineages diverged. Tradition­ erect forms; as might be expected, the angle re­ ally, the theropods and the sauropodomorphs mained intermediate in pterosaurs. As the tibia have been grouped in a single order, Sauris- assumed the primary weight-bearing function chia, which some cladistic studies (cf. Benton, of the lower hind limb, the fibula gradually be­ 1990a) seem to indicate is monophyletic at a came reduced. The astragalus eventually devel­ level above the Ornithischia. Benton lists 10 oped an ascending process and became firmly saurischian autapomorphies, but they are not affixed to the tibia, while the calcaneum shrank contrasted with corresponding ornithischian along with the fibula. The mesotarsal hinge be­ autapomorphies. Considering the enormous dif­ tween the proximal and distal tarsals was there­ ferences between theropods and sauropodo­ by converted from a joint that allowed the pes morphs in their gross morphology and lifestyle, to flex laterally to one that allowed it to flex I agree with Charig, Attridge & Crompton parallel to the direction of motion. (1965) and Charig (1982) that their lineages di­ verged well before the first prosauropods and It should be noted that the changes required theropods appear in the fossil record. Further­ for a sprawling, primitive-mesotarsal hind limb more, if the scenario for theropod origins pro­ to become a fully erect AM hind limb are pri­ vided here is reasonably correct, then thero­ marily geometric, and could certainly have oc­ pods and sauropodomorphs were even more curred independently in more than one line­ distantly related than Charig, et al. previously age. Possession of a fully erect AM hind limb imagined. is thus not necessarily a synapomorphy uniting the three dinosaurian lineages into a clade Sauropodomorphs were large, quadrupedal above the proterosuchian level. herbivores with small heads, elongate necks, Because of the missing fossil record, it is dif­ and functionally pentadactyl manus and pedes ficult to synchronize the changes in the hind (in prosauropods, pedal digit V is reduced or limb with corresponding changes that may have vestigial). Theropods were small to large bipe­ been occurring in the forelimb. In proterosuchi- dal carnivores with relatively large heads, short ans, the hind limb was larger than the forelimb to moderately long necks, functionally tri- or and the more important locomotor organ, so even didactyi manus, and functionally tridactyl any changes to the forelimb need not have pedes. The anatomical feature that compelled

Dinosaur Phytogeny 74 Mesozoic Meanderings #2 earlier paleontologists to unite sauropodo- 1986), and others, cladistic analysis of the Orni­ morphs and theropods in the order Saurischia, thischia has become something of a classroom namely, the "saurischian" pelvis, is actually a exercise. No less than five slightly different orni- plesiomorphic character retained by both thischian cladograms are exhibited by Benton, groups from nonarchosaurian diapsids. Derived (1990a: 27). There is little doubt that the orni- structural differences between sauropodo- thischian suborders belong together, but their morph and theropod pelves abound: Sauropod- interrelationships remain controversial. omorphs possessed broad, brachyiliac pelves Be this as it may, the relationship of the orni- with relatively short, massive, apronlike pubes thischians to the other archosaurs is ambigu­ and ischia. Theropods had narrow, dolichoiliac ous, largely because of the irritatingly bad fossil pelves with long pubes and slender ischia. Oth­ record. Some workers (Bakker & Galton, 1974; er significant anatomical differences can be Bonaparte, 1976; Paul, 1984; Cooper, 1985; found in the skulls, the limbs, the carpi and Bakker, 1986) have considered the Ornithischia tarsi, and the vertebral columns. Placing such closely related to the Sauropodomorpha, via disparate animals in the same order strikes me the Prosauropoda; others (e.g., Gauthier, as egregious as placing carnivores and ele­ 1986a) consider the group less closely related phants in the same order of mammals because to the theropods and sauropodomorphs than they share a similar hip structure. those two groups are related to each other (this As mentioned in an earlier section, a genera­ is die traditional viewpoint, of course). The tion of paleontologists at one time believed that third possibility, that the Ornithischia and the some prosauropods possessed theropodlike Theropoda are more closely related to each teeth, because such teeth were found in associa­ other than either is to the Sauropodomorpha, tion with prosauropod postcranial material. has received surprisingly little currency. This is These are now recognized as the shed teeth of odd, because one of the most primitive ornithis- large archosaurian carnivores, such as rauisu- chians (though not the earliest), Lesothosaums, chians, ornithosuchians, and herrerasaurians; is not terribly difficult to derive from a suitably but the belief that theropods and prosauropods primitive theropodomorph. A major obstacle to were closely related has not entirely disap­ overcome is the transition from carnivory to peared. herbivory, which is also one of the obstacles to In this work, the order Saurischia is discard­ a close relationship between the theropods and ed, and its two subdivisions, the Sauropodomor- the sauropodomorphs. In keeping with the am­ pha and the Theropoda, are essentially raised biguity of ornithischian relationships within the in rank to superorders; the Theropoda is actual­ Archosauria, I have raised 86616/5 order to a ly replaced by the parasuperorder Theropodo- superorder, and raised its five recognized sub­ morpha, a new group that includes the orders to orders. These five ornithischian or­ Theropoda as an order and also includes the ders represent five quite distinctive Baupldne various ancestral arboreal and volant forms that definitely require ordinal status among the from which I assert the familiar theropods were dinosaurs. As a superorder, the Ornithischia ac­ descended. Among these are the earliest and quires the same taxonomic level as the other most primitive known nonthecodontian archo- two dinosaurian groups. saurs, namely, Cosesaurus, Megalancosaurus, The remainder of this section deals primari­ and Longisquama, which clearly require at ly with the phylogeny of the theropodomorphs; least one new archosaurian order and perhaps the phylogenies of the sauropodomorphs and one new order each. I call their new paraorder the ornithischians are covered in subsequent Basitheropoda to emphasize its ancestral posi­ sections. Theropodomorph phylogeny is inti­ tion at the base of the Theropodomorpha. mately connected with the origin of bipedality, The second traditional dinosaurian order, endothermy, and flight in birds, so the discus­ the Ornithischia, is a well diagnosed monophy- sion will focus on those aspects first. letic assemblage (cf. Benton, 1990a). Following the work of Cooper (1985), Sereno (1984,

Parainfraclass Archosauria Cope, 1869 75 Dinosaur Phylogeny evolution as flightless forms after diverging THE ORIGINS OF AVIAN FUGHT from the main avian lineage. The proximate cause of the evolution of The discovery of Archaeopteryx in the 19th flight is predation. This is just as true for in­ century brought the reptilian ancestry of birds sects (the "ultimate" prey animals) as it is for into very sharp focus, and arguments that birds bats, birds, and pterosaurs: No other plausible were closely related to dinosaurs were soon cause, such as the quests for food and living brought forth (Huxley, 1868, 1870). In his ex­ space, has the immediacy of a fast and success­ haustive work, The , Heilmann ful escape from something that wants to eat (1927) examined all the known archosaur you. On the other hand, because the metabolic groups as potential avian ancestors and con­ cost of flight is high, a population of flying ani­ cluded that birds must have originated within mals thrust into a regime from which predation the Pseudosuchia, that is, among bipedal theco- pressure is absent, such as island isolation, will dontians (as they were then understood). The quickly evolve flightless forms, unless they are discovery of the very birdlike theropod Deinon- so highly adapted to flight that they cannot. ychus (Ostrom, 1970), as well as new speci­ The re-evolution of flightless forms in the ab­ mens of Archaeopteryx (cf. Ostrom, 1985), re­ sence of predation strongly supports the thesis turned the theropods to center stage as avian that predation is the proximate cause of the ancestors, where they have remained ever evolution of flight. since. Given the strikingly close anatomical re­ semblance between Archaeopteryx and the dei- Since most animals are subject to predation, nonychosaur theropods (Ostrom, 1976), it is in­ there is considerable selection pressure to deed difficult to imagine how any group other evolve the ability to fly. I cannot comment on than the theropods could henceforth be consid­ the evolution of flight in insects, but among the ered for avian ancestry. extant vertebrates each of the major classes, from bony fish to mammals, exhibits gliding or Any scenario of bird origins must address flying forms. As might be expected, such volant several questions. Among these are the origin creatures are small and lightweight; the evolu­ and evolution of the fully erect bipedal stance, tion of flight by large, heavy vertebrates is al­ of feathers, of avian endothermy, and of avian most certainly impossible. This is not to say aerodynamics (Charig, 1985). Two scenarios that flying forms cannot attain large size, but have addressed these questions with some suc­ only that they surely did not originate that way. cess: the terrestrial, or "ground-up" scenario Two excellent books on the origin and evolu­ (Ostrom, 1976), and the arboreal, or "trees- tion of flight have recently been published: The down" scenario. Of these, the latter has been Beginnings of Birds (Hecht, Ostrom, Viohl & in existence in one form or another since the Wellnhofer, eds., 1985) and 19th century (cf. Bock, 1985). I have not found and the Evolution of Flight (Padian, ed., 1986). the terrestrial scenario at all convincing, simply It is primarily from these two sources that I because it seems physically unfeasible. All of have arrived at my own opinions on the origins the manifold adaptations for flight—pneumatic of flight in birds and pterosaurs. In addition, I skeleton, bipedality, flight feathers, endother­ was heavily influenced by Paul's (1984, 1988b) my, wing-stroke articulation of the forelimb, most curious and unconventional notion that and so forth—would have had to evolve for oth­ some theropods were secondarily flightless er reasons and converge miraculously in the (1988b: 200). Not only do I agree with him, but single taxon that was the first flying bird. In ad­ I think that he did not take the idea far dition, the creature itself would have had to enough. All the theropods (specifically, the fight gravity to become airborne. Modern birds order Theropoda as described herein) can be can do this, because they have 150 million understood as having evolved from volant years of evolution behind them, but I just can­ forms, although some underwent considerable not see the first bird doing this. It would be as unlikely as seeing a diver burst up out of the swimming pool to land on the diving board.

Dinosaur Phylogeny 76 Mesozoic Meanderings #2 So I do not question the theory that flight endothermy is extremely equivocal. We do evolved "trees down." But the versions of this know, however, that extant birds are consum­ scenario that I have examined have left a few mate , and we are fairly certain that nagging questions that I hope my own version— the earliest archosaurs were ectotherms, be­ or Just So Story—with its attendant phylogeny cause extant crocodilians—the closest living ar- of the theropods and birds, will clarify. My pro­ chosaurian relatives of birds—are. cedure is to show how the major anatomical It is also manifestly clear that a complicated and biological features of birds could plausibly physiological regime such as avian endothermy have arisen as preadaptations that, with the pas­ could not have arisen all at once. It is probably sage of time, impelled at least one lineage of true, I think, that avian flight and avian endo­ small, sprawling archosaurs to evolve feathered thermy evolved in parallel, and by no means flying forms. particularly rapidly or straightforwardly. Inter­ Gauthier & Padian (1985: 192) summarized mediate stages in the evolution of birds must some of my questions about the arboreal theo­ have exhibited intermediate kinds of endother­ ry as follows: "[Proponents of the idea that avi­ my, but their exact nature is at present utterly an flight began in trees face a difficult chal­ unavailable from the fossil record. lenge: they must explain why so many features Most workers recognize that powered flight of modern birds, usually deemed to have is impossible without a capable of evolved in the context of flight and arboreality, sustained activity. It is difficult to imagine an are present in non-flying coelurosaurian sister ectothermic or poikilothermic flying animal groups of birds; and they must grapple with the grounded until the morning sun raises its body absence of any obvious arboreal adaptations in temperature to the point where it can take off. Archaeopteryx." I answer the first part of the It is equally hard to envision how an unstable challenge by asserting that the "coelurosaurian flier could keep itself aloft _ if it required long sister groups" were the flightless descendants of pauses between bursts of activity. All modern volant forms at various stages in the evolution flying birds use their wings and tail feathers to of powered flight; this is why they possessed avi­ adjust and change course instantaneously in re­ an features. I answer the second part with the sponse to the vagaries of air currents, the at­ question, "How arboreal is 'arboreal'?" Do we tacks of predators, and the escape tactics of mean that the proto-birds were permanent resi­ prey. Anatomical features that indicate pow­ dents in an arboreal regime, feeding, mating, ered flight in a fossil vertebrate may therefore and nesting in the trees? Or do we mean only be taken as strong evidence for an aerobic me­ that the proto-birds habitually sought refuge tabolism and a fairly high level of endothermy. from predators in the trees but otherwise car­ Stable, gliding flight is another story, howev­ ried out most of their activities on the ground? er. Since there are extant flying fish, gliding Arboreality is notoriously difficult to deduce frogs, gliding lizards, and gliding snakes, and from skeletal anatomy alone. Given only the gliding reptiles are well known in the fossil rec­ skeletons of a chipmunk and a squirrel, could ord, it is clear that neither an aerobic metabo­ we identify which is the arboreal form? The lism nor endothermy are prerequisites for the best we can do with regard to Archaeopteryx is evolution of gliding. A gliding ectotherm, even to note it has no known feature that would pre­ one with a two- or three-chambered heart, clude an arboreal lifestyle. could while in flight recover from the burst of aerobic activity that launched it and prepare it­ Endothermy and Feathers self for its next burst of activity. If birds (and Despite an entire AAAS symposium held in pterosaurs) originated as stable gliders, they 1978 (Thomas & Olson, eds., 1980), we still un­ need not have originated as full endotherms. derstand very little about the origins of endo­ On the other hand, the Permian period, thermy and whether, for example, dinosaurs which immediately preceded the initial radia­ and other non-avian archosaurs were endother- tion of the archosaurs, was a time of climatic mic animals. This is because fossil evidence for cooling and glaciation (Stanley, 1987: 90-107).

Parainfraclass Archosauria Cope, 1869 77 Dinosaur Phylogeny During the earlier period, the opened with a fresh therapsid radiation, which earth had experienced a more or less uniformly eventually led to the appearance of the first tropical climate favorable to the worldwide mammals. Likewise, there was an archosaur ra­ spread of ectothenns. The Permian cooling, diation, which eventually led to the appearance during which the earth became partitioned into of die advanced thecodontians, dinosaurs, and latitudinal climatic zones from equatorial/tropi­ birds. As with the radiation of the first mam­ cal to polar/, severely challenged the ecto­ mals, the details of the Early Triassic archo­ thenns caught in the temperate and arctic re­ saur radiation are largely missing from the fos­ gions. Most of those ectothenns responded by sil record, because the animals were small and becoming extinct, but some groups survived by did not inhabit areas where they were likely to transfering their habitats equatorward, by evolv­ be preserved. ing the ability to hibernate during the winter There is no way to determine at what stage season, or by acquiring a rudimentary kind of in the evolution of endothermy an insulatory endothermy. For example, the widespread radi­ pelage was acquired. I assume such a pelage ation of therapsids during the Permian is partly would have evolved at an early stage, because accounted for by their assumed facultative en­ the need to conserve body heat would be very dothermy (Stanley, 1987:95-96). important to an evolving in which I contend that some of the earliest archo- die physiological mechanisms for generating saurs—proterosuchians, as described in this body heat were not as efficient as in extant en­ work—also acquired a rudimentary endother­ dotherms. On the other hand, an insulating pel­ my in response to the Late Permian cooling, in­ age would probably not have evolved in ecto­ dependently of but perhaps later than the the­ thenns, because it would prevent external heat rapsids. Those first-stage endotherms must from entering the body, which is undesirable have possessed four-chambered hearts, and only when the animal is in danger of overheat­ their lineage had already diverged from that ing. In extant ectothenns, overheating is usually leading to the more advanced thecodontians. prevented by behavioral mechanisms (such as And they would have been small forms with seeking shade, burrowing, and so forth). die potential for rapid, radiative evolution un­ In the final analysis, it is impossible to de­ der the appropriate conditions. Therapsids evi­ cide whether feathers appeared before or after dently evolved hair for insulation; early primi­ first-stage endothermy at the proterosuchian- tively endothermic proterosuchians may have theropodomorph transition. The earliest feath­ acquired a pelage of thin, elongate scales for erlike scales may have evolved in conjunction the same purpose. Competition with the therap­ with gliding in ectothermic proterosuchians, lat­ sids, particularly predation by the larger therap­ er developing into an overall insulating pelage sids, would have forced some of those early ar- in primitive theropodomorphs; or featherlike chosaurs into an arboreal lifestyle, initiating scales may have evolved initially for insulation the sequence of evolutionary steps that ulti­ and became elaborated later into appendages mately led to birds. for gliding. The Permian ended with a tremendous mass The most primitive "feadiered" creature extinction (Stanley, 1987: 90-107), the terrestri­ known is the small Longisquama insignis from al episode of which left the earth virtually de­ die Late Triassic of Russia (originally de­ void of large therapsid predators (Stanley, scribed as from die Early Triassic but later re- 1987: 99). Sloan (as cited by Stanley) has dated) by paleoentomologist A. G. Sharov ascribed an episodic pattern to the Late Per­ (1970). The type specimen is not accessible to mian therapsid . This may have re­ me, but photographs of both part and counter­ sulted from the evolution of therapsid endo­ part slabs were published in a popular book on thermy in discrete stages as the climate slowly prehistoric reptiles (Benton, 1990b: 86, 87). As but continuously cooled. A similar pattern may described by Sharov, the skull of Longisquama have prevailed among the primitively endo­ possessed temporal, postorbital, antorbital, and thermic proterosuchians. The Early Triassic mandibular fenestrae, placing it well within the

Dinosaur Phytogeny 78 Mesozoic Meanderings #2 Archosauria. Only the forequarters of the ani­ of feathers. Their position in a double row on mal were preserved; the caudal dorsal verte­ the back suggests that they were homologous to brae, pelvis, hind limbs, and tail are absent. the parasagittal dermal scutes characteristic of Sharov figured Longisquama with a prominent many thecodontians, and they may have been furcula and relatively large, pentadactyl fore- worked by dermal musculature homologous to limbs. The most dramatic feature of the speci­ that of extant crocodilians. Their existence also men, however, is the unmistakeable impression suggests that the evolution of featherlike scales of long, featherlike scales projecting from the may have resulted in a radiation of gliding pro- dorsal region. Sharov interpreted these as hav­ terosuchians or basitheropods that used their ing been attached to the back in life, where "feathers" in a variety of ways. they functioned as a parachute to break the ani­ In a study of avian aerodynamics, Balda, mal's fall as it leaped among the trees. This Caple & Willis (1985) have cast doubt on the mode of life was recently elaborated by Hau­ ability of feathered gliders to make the evolu­ bold & Buffetaut (1987), who declared that tionary transition to powered flight. The exist­ Longisquama possessed a double row of dorsal ence of dorsal feathers in Longisquama sug­ scales that could be spread into horizontal glid­ gests how this transition may have occurred. I ing "wings" by dermal musculature. return to this subject below. At first I was not convinced that either Shar- Tail-Gliding ov*s or Haubold & Buffetaut's interpretation Published studies of the origin of flight in was correct. The orientation of the featherlike birds have concentrated on their cursorial abili­ scales relative to the forelimbs raised the possi­ ty and on their wings (cf. Peters & Gutmann, bility that they were attached to the forelimbs 1985); I know of no study that assesses the instead of the back and lay across the body ac­ value of a feathered tail of a kind similar to cidentally. But photographs of fossil impres­ that possessed by Archafopteryx as an airfoil. sions of other Longisquama "wings" published Yet the development of a lateral fringe of long by Haubold & Buffetaut show that the tips of featherlike scales on the tail was surely the first the feathers curved backward in life. The orien­ aerial adaptation to evolve in a primitive, arbor­ tation of the forelimbs of the type specimen eal archosaur. Like the fletching of an arrow, makes it virtually certain that had the feathers and without providing much lift, such a tail projected back from the forelimbs, they would would have given balance, direction, and stabili­ have been preserved with their tips oriented for­ ty to an animal leaping among fronds and tree ward. So the most likely location for Longisqua­ branches. When properly oriented, it would ma's wings is indeed the dorsal region. also have served as a rudimentary parachute to On the other hand, it does seem as if the break long falls; and pulling it up into the slip­ specimen's skull was displaced upward when stream like an aileron would have pitched the flattened during fossilization. The life restora­ glider's body upward for a landing on a vertical tions commonly seen in popular books (e.g., treetrunk. Benton, 1990b: 86), all based on Sharov's origi­ nal life restoration (1970: fig. 4) showing the Furthermore, such a tail would have speedi­ head with a prominent parietal-squamosal pro­ ly acquired a secondary role as a display organ jection backward over the neck, may be incor­ for sexual selection. By the beginning of the Tri- rect. The skull could instead resemble that of a assic, tail-gliding, feathered archosaurs could more "orthodox" small theropod or bird, once have radiated into hundreds of species with a the distortions are corrected. And I would not cosmopolitan distribution. Each species was be at all surprised if it turns out that Longisqua­ the potential progenitor of a distinct clade of ma possessed long, fully erect hind limbs and a archosaurs. Some actually were; the others long, feathered tail. More specimens are need­ eventually became extinct, replaced by the ed to decide these issues. more efficient fliers that soon evolved. Archosaurs plesiomorphically had long, The thin, elongate scales of Longisquama un­ moderately flexible tails and a marked size dis- doubtedly derive from a stage in the evolution

Parainfraclass Archosauria Cope, 1869 79 Dinosaur Phytogeny parity between the smaller fore and the larger were dismissed as artifactual by Sanz & Lopez- hind limbs. Stiffening the tail distally would im­ Martinez, but I am not so sure. My inclination prove its utility as an airfoil, but improved con­ is to give Cosesaums the benefit of the doubt trol of the stiffened airfoil would require inter­ and include it provisionally as the most primi­ vertebral flexibility at the caudal base. Proxi- tive member of the Basitheropoda. mally flexible but distally stiffened tails are found in all theropods, particularly tetanurans Grasping Forelimbs and Canard Wings (Rowe & Gauthier, 1990). The need to control Profound difficulties confront all attempts the tail airfoil would result in more efficient to derive die avian wing from the grasping ther- and dynamic caudifemoral musculature, a pre­ opod forelimb. The transition from forelimbs adaptation for erect, bipedal, cursorial locomo­ as feathered -traps to organs of flight in tion. Archaeopteryx (Bakker, 1975; recanted, 1986), for example, is far too unlikely for serious con­ One possible tail-gliding archosaur was de­ sideration. All known "orthodox" theropods scribed from the Middle Triassic () of possessed forelimbs much too small to have Spain by Ellenberger & de Villalta (1974) and been preadapted for any kind of flight, particu­ in two further papers by Ellenberger (1977, larly since those theropods were mostly large 1978, neither of which I have yet been able to to very large animals that would have required obtain). Cosesaums aviceps was initially hailed impossibly huge wings and musculature to fly. as a probable avian ancestor, an assessment re­ , the smallest "orthodox" thero- butted by Olsen (1979), who classified it as a pod, is the only one known whose size fell com­ small eosuchian. Sanz & Lopez-Martinez fortably into the range of extant birds (Callison (1984) essentially agreed with Olsen (without & Quimby, 1984), but its forelimbs were much citing his work) when they classifed Cosesaums too small to serve as wings (Ostrom, 1978). In­ as a juvenile prolacertiform. Molnar (1985), deed, the primary (though not exclusive) evolu­ meanwhile, noted the lack of eosuchian char­ tionary trend was for theropod forelimbs to be­ acters and rejected Olsen's identification. He come smaller rather than larger, particularly further noted the presence of a small antorbital among the carnosaurs (Tucker, 1938). In the fenestra, visible in Ellenberger & de Villalta's scenario presented here, the transition from original photographs. The presence of an antor­ quadrupedal tail-gliding basitheropod to a bital fenestra makes Cosesaums an archosaur; form in which die forelimbs possessed both a the presence of prolacertiform characters grasping and an airfoil function occurs quite (such as vertebral counts and limb ratios) can naturally. easily be attributed to plesiomorphy. As Mol­ nar noted, die skull of the specimen does show A leaping arboreal quadrupedal tail-glider a certain similarity to that of Megalancosaums is aimed head first at its eventual landing point. preonensis (Calzavara, Muscio & Wild, 1980), a Regardless of whether it lands forefeet-first or problematic Late Triassic archosaur from Italy. uses its tail to orient its body for a four-point landing, its forelimbs must play a dominant If I were called on to display a specimen of role at the termination of its trajectory, they a tail-gliding proterosuchian or theropodo- are perfectly positioned to grasp and hold on morph, Cosesaums probably comes the closest to a frond, branch, or treetrunk. As ideal ap­ to my idea of what one might look like. In size pendages for climbing in an arboreal habitat, and general appearance, the specimen strongly large, strong grasping forelimbs would have resembles Mesenosaums, Sharovipteryx, and evolved as natural improvements on the plesio- Scleromochlus. Most interestingly, Ellenberger morphic small forelimbs of the earliest tail-glid­ (1977, 1978) figured Cosesaums with feather ers. Such forelimbs are in fact observed in the impressions, particularly along the tail, to sup­ type specimen of the primitive archosaur Mega­ port his contention that it was related to the lancosaums (Calzavara, Muscio & Wild, 1980). birdlike trackmakers from the Lower Storm- berg he had previously described (Ellenberger, Furthermore, feathers or featherlike scales 1970, 1972, 1974). The feather impressions on the outstretched forelimbs would have been

Dinosaur Phytogeny 80 Mesozoic Meanderings #2 perfectly placed to serve as canard airfoils to ing forms into which the archosaurs radiated adjust the direction of the tail-glider's trajec­ during the Triassic. I do not find Balda, et al.'s tory. Elongation of the feathers would have ac­ argument very convincing; it is more straightfor­ companied the increase in forelimb size, and a ward for true wings to have developed from gliding form resembling Protoavis texensis gliding wings, as indicated by Rayner (1985a, (Chatterjee, 1991) could have evolved quite 1985b). Rayner's accounts of the aerodynamics rapidly, well before the end of the Triassic. of the gliding-to-flapping transition are emi­ Like tail-gliders, canard-wing gliders were nently clear, readable, and compelling. I hope small forms that must have radiated into hun­ they are right, so that the dorsal-wing model dreds of species, eventually displacing the tail- set forth above proves unnecessary. gliders much as extant passerine birds have par­ One detail confronts any phylogeny in which tially displaced the less-derived avian groups. theropods evolve from small, feathered forms: Canard-wing gliders equipped with tail airfoils Why haven't feather impressions been found would have been aerodynamically stable fliers with theropods other than Archaeopteryxl Such for the same reasons that paper and balsa- feathers were searched for by Ostrom (1978) in wood gliders are. With small adjustments of Compsognathus, but no trace was discovered. their wings, they could have soared great dis­ Paul (1988b: 121-123) suggests that the larger tances once launched. And as the canard wings theropods did not need an insulative pelage, adapted to gliding flight, they would have just as large extant mammals that live in tropi­ evolved naturally into the larger wings observed cal climates do not need hair. Skin impressions in Archaeopteryr. powerful appendages with of large theropods show a scaly integument but which the animal exercised considerable con­ absolutely no feathers. Paul's life restorations trol over the direction and length of its flight of the smaller theropods and lagosuchians, how­ path. ever, are imaginatively supplied with feathers, Balda, Caple & Willis (198S) assert that fore- against which, he asserts/ the fossil record is limbs adapted for gliding would not be prea- simply badly biased. I am convinced that small dapted to evolve into true wings, which provide theropods will eventually be discovered with both lift and thrust for flight. In gliding flight, feather impressions, but I can offer no reason the wings provide only lift; gravity and air cur­ to think this other than my phylogeny. rents supply the energy of motion that the The Furcula wings convert into lift. Should Balda, et al. Clavicles were plesiomorphic in archosaurs prove correct, then Longisquama shows how (Carroll, 1988), and their function of bracing protoavian forelimbs might have evolved into the pectoral girdle against the sternal elements true wings. Forelimb feathers are not the only preadapted them as shock absorbers for arbore­ ones that can elongate into gliding wings; as al leaping (Haubold & Buffetaut, 1987). The noted above, featherlike scales in the dorsal re­ shock-absorbing function of the clavicles im­ gion of Longisquama were elongated into erec­ proved when they fused into a furcula, and it tile wings. Such dorsal "wings" would have kept continued to improve incrementally as the fur­ the protoavian aloft as easily as elongate fore­ cula became the unique springlike bone of mod­ limb feathers. The forelimbs could then have ern birds. In extant birds, die furcula stores en­ evolved a true canard function, as mobile anter­ ergy for the return stroke of the wings (K. ior auxiliary wings helping to steer the animal Campbell, pers. comm.), and its shock-absorb­ in flight. Not needed as primary flight organs, ing function is now all but lost. the forelimbs would have been freer to evolve into flapping appendages. As the forelimbs as­ Thulborn (1984) was able to identify furcu- sumed a larger role in flying, the dorsal lae in several theropod genera, including even "wings" would have diminshed, eventually van­ tyrannosaurids, but their absence in most thero­ ishing entirely. pod taxa does not preclude a close relationship between theropods and birds, as Heilmann I must confess that I believe Longisquama (1927: 183) maintained. Reduction or loss of simply to have been one of a multitude of glid­

Parainfraclass Archosauria Cope, 1869 81 Dinosaur Phylogeny the clavicles or furcula can be expected in saurs possessed relatively large hind limbs plesi- flightless descendants of arboreal gliders and omorphically, and the smaller, lightweight fliers. forms were surely capable of rapid bipedal pro­ gression when the need arose. A potential for Bipedal Stance this kind of locomotion has been ascribed to Birds and Homo sapiens are the only extant Late Permian eosuchians such as Heleosaums vertebrates that are obligatory bipeds; jumping (CarrolL 1976). The scenario presented above mice and rats are nearly obligatory bipeds. In for the origin of canard and gliding wings current bird phytogenies, obligatory bipedality makes it relatively easy to see how a small ar­ is considered a plesiomorphic character ac­ boreal form would come to rely less and less quired by birds from theropod ancestors. How on its forelimbs for walking and running. this unusual and hazardous form of locomotion Grounded basitheropods, with their forelimbs might have arisen in theropods, however, is usu­ encumbered by feathers and specialized for ally dealt with ad hoc: The theropods were bi­ grasping, climbing, and gliding, would come to pedal because they acquired the character ple- depend exclusively on their hind limbs for cur­ siomorphically from their "thecodontian" an­ sorial locomotion. cestors—and bipedality arose in thecodontians because it just did: perhaps as an adaptation It is difficult to determine when the basither- for increased speed, or teleologically—to allow opod foot made the transition from plantigrade thecodontians to grasp prey with their fore- to digitigrade posture. Digitigrady is commonly limbs—and so forth. held to be an adaptation for increased speed in fully erect animals (Coombs, 1978; Paul, Most terrestrial vertebrates are quadrupe­ 1988b), and it is difficult to imagine a semi- dal, including the fastest (Acinonyx, Gazella, erect basitheropod in a digitigrade stance. So I Antilocapra), and quadrupedal predators have presume that the fully erect stance preceded no trouble grasping prey with their jaws. Most the digitigrade posture: By the time lagosuch- quadrupeds can occasionally assume a bipedal ians, herrerasaurians, ceratosaurs, and protoavi- stance, and many can even walk or run bipedal- forms had evolved, fully erect, digitigrade bipe­ ly for short distances, especially lightweight dality was the commonest locomotor mode lizards (Heilmann, 1927: 178), but there seems among theropodomorphs. to be little need for facultative bipedality to be­ come habitual or obligatory. A quadrupedal A subtle anatomical effect may also have stance confers locomotor stability, and injury contributed to the acquisition of bipedality to a limb will not usually immobilize a quadru­ among the archosaurs. In advanced therapsids, pedal animal. Bipedal locomotion requires ex­ such as , the vertebral column im­ ceptional balancing ability and coordination to mediately anterior to the has a rib-free avoid falling. These are all compelling reasons lumbar region, and the vertebrae are adapted why quadrupedality has remained the domi­ to restricting lateral flexion while permitting in­ nant mode of locomotion among nonavian tet- creased dorsoventral flexion (Carroll, 1988). rapods. Bipedal locomotion is not a natural This situation undoubtedly coevolved with in­ outcome of the progression from sprawling creased locomotor efficiency and speed and al­ quadruped to semi-erect quadruped to fully lowed the axial musculature, as well as the ap­ erect quadruped. Its prevalence among dino­ pendicular musculature, to participate in run­ saurs, particularly theropods, requires explana­ ning and bounding. In archosaurs, a rib-free tion. lumbar region never evolved. This limited the body's flexibility, so the axial musculature I assert that the familiar theropods were bi­ could not readily participate in running. Archo­ pedal because they descended from animals in saurs, even small ones, had to rely almost exclu­ which the forelimb was already doing something sively on limb musculature to run. In bipedal other than walking, namely, serving as an ap­ forms, the hind limbs did all the work, and the pendage for grasping, climbing, gliding, and fly­ net evolutionary effect was to greatly increase ing in small, arboreal theropodomorphs. Archo-

Dinosaur Phylogeny 82 Mesozoic Meanderings #2 the size of the already large hind limbs and metric, with the middle digit (III) remaining their associated musculature. longest and strongest and the digits on either A human runner carrying a long, heavy log side (II and IV) being almost as large. Digit I is roughly equivalent anatomically to a large typically was reduced to where it would not walking or running theropod. Theropods adapt­ contact the ground, while digit V became ves­ ed to this condition by evolving shortened bod­ tigial and even absent. This disposition of pedal ies, retaining the long tail as a counterbalance, digits defines the paraorder Theropoda in the and reducing unnecessary spinal flexibility with classification used here; digitigrade theropodo­ extra intervertebral articulations. Unneeded for morphs in which digit I retains some weight- locomotion, the forelimbs became as small as bearing function and digit V is not significantly possible without totally losing their prey-handl­ reduced are classified as lagosuchians or her- ing function. rerasaurians. Bipedality in ornithischians was not accom­ Theropodomorph digital loss also occurs in panied by skeletal pneumatization, so I do not the manus, and it roughly parallels digital loss believe the ornithischians evolved from volant in the pes. That is, theropods with functionally forms. Ornithischians may have evolved as her­ tridactyl pedes usually (though by no means al­ bivores from semi-erect proterosuchians that ways) possessed a functionally tridactyl manus. used their forelimbs and hands to select, pluck, This suggests an ontogenetic parallelism be­ and manipulate the edible parts of plants. Tenu­ tween fore and hind limbs, but if so it is not ously supporting this hypothesis is the observa­ perfect. Whereas the dominant pedal digits tion that evolutionary loss of manual digits in were II, III, and IV, the dominant manual ornithischians was not nearly as thorough as in digits are considered to be I, II, and III. theropodomorphs. Many large forms, such as In extant birds, ontogenetic studies show Iguanodon, retained a pentadactyl manus. that the digits in the wings, which are fused in Some of the heavier ornithischians became se­ all birds except juvenile -hoatzins (Opisthoco- condarily quadrupedal, an evolutionary option mus), are actually digits II-IV (Hinchliffe, open to them because they never evolved the 1977, 1985). Tarsitano & Hecht (1980) extrapo­ highly specialized forelimbs required for glid­ lated this pattern back to Archaeopteryx, assert­ ing or powered flight. Other ornithischian line­ ing that its digits should therefore also be num­ ages, such as the ankylosaurs and stegosaurs, bered II-IV, and Thulborn & Hamley (1982) may not have evolved from bipedal forms at all. suggested that the manual digits in all manually Poposaurians are also thought to have tridactyl theropods should likewise be num­ evolved a bipedal stance, but their limb ele­ bered II-IV. The phyletic significance of this ments are not yet well known. The degree of bi­ seemingly trivial debate is that if the digits were pedality prevalent among poposaurians and I—III in theropods and Archaeopteryx, then the how this bipedality may have evolved cannot common ancestry of birds and theropods was yet be determined with confidence. considerably more remote than if the digits were II-IV (Hinchliffe, 1985). Unfortunately, Manual and Pedal Digits not enough primitive tetradactyl theropod man­ Dinosaurs in general and theropodomorphs us are known to settle this question. Those that in particular progressively reduced and then are known, among the ceratosaurs for example, lost some of the digits on both their fore and seem to possess the I—III pattern with a re­ hind limbs. In the hind limbs, digital reduction duced digit IV rather than a II-IV pattern with is commonly held to be an adaptation for a reduced digit I (Rowe & Gauthier, 1990). speed: Removal of unnecessary weight from the extremities decreases their moment of iner­ In all known "orthodox" theropods with tri­ tia around the point of articulation with the dactyl mani, the manus matches that of Ar­ body, thereby increasing the efficiency of the chaeopteryx in phalangeal counts and morpho­ appendicular musculature (Coombs, 1978). In logical conformation of the individual phalang­ most theropods, the pes remained quite sym­ es. The manus of Archaeopteryx is so similar to those of deinonychosaurs, in fact, that I enthusi-

Parainf raclass Archosauria Cope, 1869 83 Dinosaur Phylogeny astically support Paul's (1984, 1988b) conten­ Wings tion that Archaeopteryx is best thought of as a The similarity of the foreiimb anatomy of primitive deinonychosaur. In die classification certain advanced theropods, such as Deinony- presented here, I consider Archaeopterygidae chus, to that of Archaeopteryx was well docu­ to be a parafamily within the Deinonycho- mented by Gauthier & Padian (1985). Its sauria, ancestral to the Dromaeosauridae and origination in theropods, however, is unclear Troodontidae. Details of skull structure (e.g., until it is realized that it developed first in jugal with reduced or absent ascending pro­ volant theropods to make flapping, powered cess: cf. Buhler, 1985; Paul, 1988b: 354 actually flight more efficient. Archaeopteryx was surely a supplies one!) exclude Archaeopteryx itself capable flier (cf. various articles in Hecht, Os­ from ancestry of any other known deinonycho­ trom, Viohl & Wellnhofer, eds., 1985) whose saur, but there were probably dozens or even foreiimb retained an excellent grasping func­ hundreds of archaeopterygid species world­ tion for arboreal climbing, and there is no rea­ wide during the Late Jurassic, one of which son to expect flightless archaeopterygid descen­ could well have been "the" ancestral dromaeo- dants to foresake this function as predators. saurid and another "the" ancestral troodontid. The digits of Archaeopteryx convincingly ally it Other Adaptations much more closely to "orthodox" theropods Orthodox scenarios for the origin of thero­ than to modern birds. If Martin's (1985) con­ pods have difficulty accounting for their pneu­ tention that Archaeopteryx is an enantiornithid matic skeletons. Volant basitheropods, howev­ bird is correct, dien perhaps all "orthodox" er, surely evolved a pneumatic skeleton as an theropods were not just flightless protoavians adaptation for more efficient flight; bone-mass but flightless enantiornithids. reduction would lower a tail-glider's momen­ tum and kinetic energy, reducing stress on the All specimens of Archaeopteryx in which the pectoral girdle when the forelimbs terminated feet are preserved show a retroverted digit I its glide. Bipedal archosaiirs that were not ther­ (Ostrom, 1985; Wellnhofer, 1991: 179, 180). I opods, such as ornithopods and (probably) po- cannot believe this is coincidental; it must be posaurians, do not exhibit the extensive skele­ because the first digit really did oppose digits tal pneumatization of theropods, because this II-IV in the foot. This strikes me as an adapta­ character is not a prerequisite for bipedality, tion for perching, and it is evidence that Ar­ and in fact thin, relatively fragile bones repre­ chaeopteryx was more arboreal than cursorial sent a structural disadvantage for large preda­ in its lifestyle. Digit I in Archaeopteryx, how­ tors. Paul (1988b) notes that theropod bone ever, is considerably smaller than digits II-IV, was denser and stronger than the bone of non- so the grip of the foot may not have been par­ predatory dinosaurs. If this is true, it can be ac­ ticularly strong. In most "orthodox" theropods, counted for as a means of overcoming the pedal digit I is peculiar in that the metatarsal structural problem of skeletal pneumaticity bone is split into an upper and a lower section that the large theropods inherited from their (Rowe & Gauthier, 1990; Molnar, Kurzanov & basitheropod forebears. Dong, 1990; Barsbold, Maryanska & Osm61- ska, 1990; Ostrom, 1990) or missing entirely Small, arboreal climbers and leapers require (Barsbold & Osmblska, 1990). This suggests excellent vision and coordination. These char­ that pedal digit I, unneeded for perching in cur­ acteristics must have coevolved with the semi- sorial theropods, secondarily returned to a erect and fully erect stance in basitheropods, more forward orientation. The split metatarsal when the forelimbs were used for grasping and I is yet another remnant of the basitheropod ar­ climbing even before they acquired any volant boreal volant lifestyle that survived vestigially function. Basitheropods thus became preadapt- in theropods. ed for the demands of tail-gliding, gliding, and powered flight. Cranial characters that seem to indicate these kinds of sensory-neural improve­ ments have been documented in the protoavi-

Dinosaur Phytogeny 84 Mesozoic Meanderings #2 form theropod Protoavis texensis by Chatterjee One hundred fifty million years thus yields (1991) and used as evidence of a basal position 33 or 34 complete species turnovers among the for Protoavis with respect to the class Aves. dinosaurs, which when multiplied by 6000 spe­ Postcranially, Protoavis is solidly a core-group cies per epoch yields a grand total of about theropod. 200,000 dinosaur species that ever lived. Assum­ ing an average of 10 species per genus—some extant vertebrate genera have more than 30 COMMENTS ON DINOSAUR DIVERSITY species per genus, others have only one or AND EXTINCTION two—this yields 20,000 genera: nearly an order of magnitude more than the maximum figure How many dinosaurs were there? This ques­ calculated by Dodson. tion was recently addressed by Dodson (1990), What is the source of this huge discrepancy? who applied statistical methods and a few seem­ I see nothing unreasonable about the back-of- ingly reasonable assumptions about collection the-envelope calculations outlined above. Dod- and preservation biases to the dinosaur fossil son's assumptions about preservation biases record. The total number of dinosaur genera may, however, be too low. There is not enough that ever lived, according to his calculations, space here to question all his assumptions in was somewhere between 645 and 3285, with a detail; that is the stuff of a separate paper. In­ most probable value between 900 and 1200. stead, I will offer my own thoughts about such I was asked the same question in an inter­ biases, and see whether the discrepancy can view for a popular dinosaur television show, thereby be explained. and I estimated the answer in the following One factor not considered in calculating pre- way: Dinosaurs dominated the world's terrestri­ servational biases is that all known dinosaur fos­ al biota for approximately 150 million years. Ex­ sils necessarily occur in depositional environ­ tant vertebrates that likewise dominate their do­ ments: fluviatile, lacustrine, or aeolian. Such en­ mains are bony fish, birds, and mammals, and vironments presently comprise about 10% of there are several thousand species of each: the earth's total land area (a crude estimate over 20,000 species of fish, 9672 species of based on visual examination of world maps); at birds, over 3000 species of mammals. The pres­ any given time, 90% of the world is being erod­ ent epoch is, in my opinion, one of average ver­ ed away. Epicontinental seas, such as the one tebrate diversity, neither particularly depauper­ that covered during the Creta­ ate nor particularly abundant, and "several ceous Period, foster the development of fluvia­ thousand species" seems to be a number that tile and lacustrine depositional regions, and the characterizes the diversity of any large verte­ fraction of earth's land area that was deposi­ brate group of worldwide distribution. Exacti­ tional then may have attained 25% (Haubold, tude is not necessary in this kind of order-of- 1990). Even so, this means that as many as 75- magnitude calculation, so I chose a figure of 90% of the dinosaur species extant in any one 6000 as a likely number of dinosaur species ex­ epoch may never be found as fossils, simply be­ tant at any one epoch. cause they did not live in depositional environ­ Dinosaur species seem to have originated, ments. Another factor is that depositional envi­ flourished, and become extinct over a period of ronments may not be particularly species-rich. no more than about 4.5 million years. There Today's tropical rain forests contain the most are four distinct dinosaur faunas known in the diverse faunas by far, but such forests are to of North America, taphonomically inimical to the preservation of a period of time spanning about 18 million fossils. years; this amounts to an average of 43 million If dinosaurs diversified into an average of years per fauna. At this time scale, even generic 6000 species per epoch, we might expect that turnover between the faunas was virtually com­ about 600-1500 species lived in or near deposi­ plete. tional environments where fossilization could occur. This places a theoretical upper bound

Parainfraclass Archosauria Cope, 1869 85 Dinosaur Phylogeny on the number of species we could in principle tend to address the questions of what caused discover. Quite a few such deposits have al­ the extinctions or of how long the extinctions ready been eroded away, taking their loads of may have lasted. While those are interesting species with them, and as a rule, the farther questions, I am more concerned here with the back we go in the Mesozoic, the fewer such de­ effect of the extinctions on Mesozoic archosaur posits remain to be excavated. Note, for exam­ phytogeny and diversification. ple, that the Upper Cretaceous provides the The broad similarities in archosaur evolutio­ largest number of dinosaur-bearing formations, nary patterns following extinction events sug­ which I ascribe to this fossilization bias. After gest that a single model might account for taking such biases into account, we are left them all. Central to this model is the existence with the handful of species per epoch that are of one or more "core groups" of small, rapidly actually present in our museum collections. evolving (tachytelic), highly diverse archosaurs The point to ponder is that enough slack exists that comprise an "evolutionary engine" from in the statistics to allow the fossil record to sup­ which the larger, more slowly evolving (brady- port either Dodson's "lowball" diversity esti­ telic) forms arise. Being small, core forms are mates or my "highball" estimates. Consequent­ seldom found as fossils, and when they are, ly, we may have to look elsewhere than the fos­ they tend to be perplexing animals that seem sil record to calculate dinosaur diversity. not to fit into any of the better-known groups. Finally, it should be noted that the bulk of Also, because they were small, core forms were species diversity in extant vertebrate groups subject to considerable predation pressure, of­ lies among the small forms. If there were only ten from their own larger descendants, which large dinosaurs, then Dodson's estimates tended to keep their evolutionary fecundity in would certainly be apt, for as he notes, they check. But when an extinction event removed agree in order of magnitude with the numbers this predation pressure, the core groups rapid­ of extant large mammals. But I contend that ly radiated to fill the void. As the new forms be­ there were many more small dinosaurs— came large and cosmopolitan, the likelihood of pigeon- and chicken-size arboreal climbing, their preservation as fossils rose, and the fossil gliding, and flying forms—than anyone has pre­ record displays their "abrupt" appearance. In viously guessed. Their existence follows from short, the fossil archosaurs that we have so far die pattern of archosaurian evolution as out­ discovered seem to be the tip of an evolution­ lined in this work. Their physical traces include ary iceberg. the unidentifiable small theropod and ornithis- chian teeth and other skeletal fragments found The Permian-Triassic (P-T) Extinction in many museum collections, and occasional When the P-T extinction took place, there footprint faunas that document a much higher were only two extant archosaur orders: the Pro- level of dinosaur diversity than do fossilized re­ terosuchia and (probably) the Basitheropoda. mains (Lull, 1953; Ellenberger, 1970, 1972, These comprised a core group from which the 1974; Olsen & Galton, 1984). Early Triassic archosaurs radiated, and they were themselves ultimately descended from a Archosaur Evolutionary Patterns Permian nonarchosaurian diapsid core group. The observed pattern of archosaur evolution The main victims of the P-T extinc­ in the Mesozoic is one of rapid radiation, fol­ tion were large therapsids, including most if lowed by apparent evolutionary stasis, followed not all of the world's top predators as well as by mass extinction, followed by rapid reradia- many groups of herbivores. The removal of tion of surviving groups (if any). There were six those forms fostered the first archosaur radia­ major extinctions that affected the archosaurs, tion, not to mention a radiation of new therap­ beginning with the one that opened the Meso­ sids, which possessed a powerful "evolutionary zoic Era and ending with the one that closed it; engine" of their own. the archosaurs were affected by some of those It must be remembered that although the extinctions more than by others. I do not in­ therapsid and archosaurian core groups re-

Dinosaur Phytogeny 86 Mesozoic Meanderings #2 mained deep in the background insofar as their archosaur orders had appeared in the fossil fossil records are concerned, they were by no record, including the Parasuchia, Aetosauria, means immune from the evolutionary process. Hupehsuchia, Crocodylia, and Lagosuchia. They were, however, reasonably immune from Other possible descendants of the proterosuchi­ the mass-extinction process. Large terrestrial an core group were ancestral pterosaurs, in­ vertebrates possess a slow evolutionary tempo cluding the Sharovipterygia and Rhamphor- and are unable to find shelter from the usual hynchoidia, which undoubtedly constituted a agents of mass extinction, such as abrupt cli­ third archosaurian core group. matic change, asteroid impact, and so forth. The proterosuchian "engine" itself gradually Their usual response to such agents is to be­ faded away, being replaced by the basithero- come extinct, and since such animals are by vir­ pods as the principal archosaurian core group. tue of their size prominent in the fossil record, The basitheropods had filled many niches as ar­ it is their simultaneous disappearance that sig­ boreal and small cursorial animals during the nals the mass extinction. New Bauplane seldom Early and Middle Triassic, and they would if ever evolve from large terrestrial vertebrates. prove important to the subsequent archosauri­ Rather, the evolution of such animals consists an fossil record. principally of "variations on a theme." I call the Triassic archosaur core group "ba­ Evolution in a core group occurs at a faster sitheropods" out of ignorance of their true di­ tempo because core-group animals are smaller, versity. They undoubtedly included a number have shorter gestation periods, take less time to of lineages, only one of which can properly be attain sexual maturity, and have larger litters called Basitheropoda: the lineage that led to than large animals. In the absence of predation, the Theropoda and ultimately the Aves. Other this is the source of radiative evolution. But it lineages, among which might be "Basisauropo- is also a wellspring of rapid evolution under da" and "Basiornithischia," led to the sauro- most other circumstances. When niches for podomorphs and ornithischians, but representa­ large forms become occupied, core-group evo­ tives of those lineages are entirely absent from lution produces other core groups instead. New the fossil record. There is no point in formally Bauplane would thus be a frequent byproduct naming such groups until at least one member of core-group evolution. The primary agent of of each can be identified. core-group extinction—if this process really oc­ curs, and is not simply an artifact of complete The Carnian-Norian (C-N) Extinction evolutionary turnover—seems to be the con­ A major extinction occurred at the boundary stant competition with other core groups, rath­ between the Carnian and Norian epochs of the er than the global extinction events that occur Late Triassic. The result of the C-N extinction every few score million years. Core-group ex­ was the removal of most of the remaining large tinction appears to be steadier and less therapsids and some nonarchosaurian diapsids. episodic than the extinctions of larger forms. Among the archosaurs, many large thecodon- tians vanished, but faunas with crocodilians, The fossil record seems to show gradual ar- large pseudosuchians, parasuchians, and aeto- chosaur diversification throughout the Early saurs persisted. (The crocodilians actually and Middle Triassic at the expense of the re­ proved to be quite a durable group, being the maining large therapsids and other nonarcho- only thecodontian order to have survived to the saurian diapsid reptiles (Benton, 1986b; Hunt, present.) Most interestingly, however, the basi- 1991). In particular, the proterosuchian part of theropod "engine" generated the herrerasauri- the core group generated a number of ground- ans, ceratosaurians, and protoaviforms, and ear­ dwelling predators, including early ornithosu- ly sauropodomorphs and ornithischians entered chians and pseudosuchians. These groups, par­ the fossil record for the first time. ticularly the pseudosuchians, gradually diversi­ fied at the expense of the therapsid and other By this time, the basitheropods and protoavi­ reptilian groups as the Triassic unfolded. By forms were probably widespread and diverse, the beginning of the Late Triassic, several more and they filled the trees with various feathered

Parainfraclass Archosauria Cope, 1869 87 Dinosaur Phytogeny climbing and gliding forms. Cursorial basithero- The Jurassic-Cretaceous (J-K) Extinction pods and protoaviforms, lagosuchians, and her- The J-K extinction is not yet well document­ rerasaurians were most likely not as diverse, ed, but one of its consequences was the disap­ but the Bauplan of a small, bipedal predator, pearance of the large diplodocids and brachio- with grasping forelimbs where it once had saurids from the northern hemisphere. Most of canard wings with claws, had become well es­ the other dinosaur groups persisted across the tablished. This body plan persisted in the para- Jurassic-Cretaceous boundary, although the order Theropoda through the end of the Me- stegosaurians did so as a relict fauna. New sozoic. Among the prey animals seized by the kinds of theropods (baryonychids, abelisaurids) smaller theropods were core-group therapsids, and oraithischians (iguanodontids, psittacosau- including the earliest true mammals. rids) appeared. Nodosaurids, previously rare, Competition from and predation by ptero­ radiated into several genera. This event may saurs may have helped to limit the evolution of have been related to the breakup of the super- climbing and gliding core-group archosaurs continent into Laurasian and Gond- during the Norian, but the protoaviform core- wanian land masses, because subsequent to the group undoubtedly flourished. Besides that or­ extinction, the fossil records of the northern der and the Theropoda, other Norian core- and southern hemispheres diverge significantly. group orders included the Lesothosauria and the earliest members of the Pachycephalosau- The Cretaceous-Tertiary (K-T) Extinction ria (Pisanosauridae and Heterodontosauridae). In terras of popular interest, this extinction event was by far the most significant for the ar­ Most emphatically not core-group archo­ chosaurs. But the most interesting question saurs, the early sauropodomorphs took over about this extinction event is not, "What the large- niche from large therapsid caused it?" but, "Why didn't the archosaurs herbivores, and they enjoyed considerable suc­ return, as they had done six times before?" In cess throughout the Mesozoic terms of the model outlined here, the answer is The Triassic-Jurassic (T-J) Extinction that the archosaur core group no longer in­ A major result of this extinction was the dis­ cluded the dinosaurian Bauplan. The small ar­ appearance of all the thecodontian orders ex­ boreal and cursorial dinosaurs had been cept the Crocodylia and possibly the Parasu- decimated throughout the Late Cretaceous by chia. Theropods, prosauropods and sauropods, competition with placental mammals—the ul­ lesothosaurians, and ankylosaurians reradiated timate "therapsid" core group—leaving as sur­ thereafter, establishing the dinosaurs as the vivors only the aerial forms: the class Aves. dominant terrestrial megafauna. The Age of Large, flightless avian predators and her­ Dinosaurs began with this extinction event. bivores (Diatryma, Phorusrhacos, Onactomis, Dinomis, and so forth) continued to evolve at The - (P-T) Extinction various times during the Tertiary, bearing the This was primarily a marine extinction, but same relationship to volant birds that large one possibly related consequence was the dis­ dinosaurs bore to core-group dinosaurs. But appearance of the prosauropods from the fos­ without grasping forelimbs, such flightless sil record. Otherwise, the dinosaurs survived avians were not true dinosaurs. Thus, after serv­ this extinction event intact. ing as dinosaur food for two-thirds of the Mesozoic Era, the mammals had gained some measure of revenge.

Dinosaur Phytogeny 88 Mesozoic Meanderings #2 Dinosaur Orders

HE THEROPODOMORPHA comprises by "orders" Ceratosauria, Carnosauria, Ornithomi- Tfar the most problematic archosaurian as­ mosauria, Oviraptorosauria, and Avimimifor- semblage. If the scenario for theropodomorph mes. In the present work, however, I employ a and bird origins described in the previous sec­ more traditional framework, because conclu­ tion proves at all accurate, then the taxonomy sive evidence for this kind of theropod polyphy- of the theropod dinosaurs may require a revi­ ly has only begun to emerge. Detailed evidence sion more radical than anything I propose here. that would allow us to disentangle the phyletic The discovery of more specimens of theropod- relationships among the theropod suborders like avians and birdlike theropods could well has presently not advanced much further than make the distinction I have drawn between the the "gut feeling" that we are only scratching Theropoda and Aves too arbitrary to be sup­ the surface. Bearing this caveat in mind, I have ported even by a traditionalist like me. In the identified four orders and paraorders among long run, the entire parasuperorder Theropodo- the theropodomorphs. morpha may, perhaps, have to be subsumed in­ Among the characteristics of theropodo­ to the class Aves. The terms "theropod" and morphs are carnivorous dentition (when pres­ "dinosaur" would lose their phyletic validity, ent); semi-erect to fully erect stance; and tarsus for I cannot imagine that birds will ever come with reduced calcaneum. Impressions of feath­ to be thought of as small, flying dinosaurs. The ers or featherlike scales may be present. The name Aves, after all, has historical priority over parasuperorder Theropodomorpha is defined Dinosauria. as the smallest clade including Megalancosau- If the methods of grouping species into rus, Longisquama, and (possibly) Cosesaurus, higher taxa that are followed in ornithological together with all the well-known theropod taxonomy were applied to theropodomorph tax­ dinosaurs, minus the clade Aves (or Carinat- onomy, then many of the suborders listed here ae), as defined in the Archosaur Phytogeny sec­ in the order Theropoda, and even some of the tion). families, would require orders of their own. Hawks (order Falconiformes) and sparrows Paraorder Basitheropoda (order Passeriformes), for example, seem to This paraorder is created for the most primi­ me considerably more alike morphologically tive theropodomorphs. With only a few re­ than do Tyrannosaurus and . It is a pe­ ferred species so far, some of which will doubt­ culiarity of paleornithological taxonomic prac­ less eventually acquire orders of their own, tice that when a fossil form is identified as a there is considerable danger that the Basither­ bird, particularly from an epoch prior to the opoda will (or already has) become a waste- Late Cretaceous, its identifier often creates a basket group for peculiar small archosaurs that monotypic order just for it. So if paleornitholo- defy classification into the better established gists can consider as orders such groups as Ar- groups. Not helping this situation is the fact chaeopterygiformes, Enantiornithiformes, Gobi- that the type specimens of the three listed spe­ pterygifonnes, and Protoaviformes, then to cies are small and difficult to study because these must eventually be added the theropod

Parainfraclass Archosauria Cope, 1869 89 Dinosaur Orders they exist only as slab impressions and cannot Order Herrerasauria be examined in three-dimensional detail. This order, originally created by Galton Among the characters to look for in a poten­ (1985a) as a theropod infraorder, includes sev­ tial basitheropod are: an antorbital fenestra eral bipedal carnivorous dinosaurs of apparent­ (plesiomorphic, but its absence would exclude ly basal but otherwise uncertain position close the specimen at once); generally avian appear­ to the Theropoda (Sues, 1990). Staurikosaums ance of the skull; relatively large, grasping fore- and are the only two herrerasau- limbs; clavicles, fused clavicles, or primitive fur- rian genera at all well understood, and they are cula; sacrum with three or even more verte­ different enough from each other to warrant brae; incipient or fully evolved AM tarsus, de­ separate families (cf. Gallon, 1985a). pending on hypothesized semi-erect or fully Excluding the herrerasaurians from the erect hind-limb stance; reduced calcaneum; Theropoda are their functionally tetradactyl pentadactyl manus and pes (plesiomorphic, but pedes, in which metacarpal I was reduced but a manus or pes with fewer digits would be a de­ not split as in the theropods. The pelvis was rived condition above the Basitheropoda); im­ brachyiliac with rather broad, apronlike, slight­ pressions of featherlike scales or feathers. Fu­ ly retroverted pubes that terminated in a foot­ ture work is necessary to better characterize like enlargement. News photographs of a re­ this order. cently discovered nearly complete Herrerasau­ rus skull from show its very thero- Order Lagosuchia podlike appearance, so a taxonomic position This group was created by Paul (1988b) to for the Herrerasauria in a theropod sister accommodate the families Lagosuchidae and group is indeed likely. Like the lagosuchians, Lagerpetonidae. Paul also included the proble­ herrerasaurians represent a theropodomorph matic genus Lewisuchus in the Lagosuchia, but lineage that diverged from the Basitheropoda most authorities now agree it represents a dis­ before pedal digit 1 was reversed. They are tinct sphenosuchian family (Crocodylia). known with certainty only from the Late Trias­ The lagosuchians seem to have been a Mid­ sic (Carnian) of , but fossil teeth dle Triassic offshoot of the lineage leading that may be refereable to herrerasaurians have from the basitheropods to the theropods prop­ a nearly worldwide distribution. The usual lack er, I know of no archosaur that could be con­ of complete material frustrates knowledge of sidered as descended from any lagosuchian tab­ these dinosaurs. ulated here. Gauthier & Padian (1985) place Lagosuchus, which is the only lagosuchian I have organized the order Herrerasauria ac­ known from reasonably complete material, be­ cording to Galton (1985a) and Sues (1990). tween the Ornithosuchidae and Pterosauria Paraorder Theropoda plus Dinosauria on the "ornithosuchian" This is the most diverse archosaurian order, branch of their archosaur cladogram. For rea­ even with the birds excluded. The fossil record sons previously stated, I believe the Or­ of the theropods begins in the Late Triassic nithosuchidae and Pterosauria do not belong and extends to the very end of the Late Creta­ here, and that Gauthier & Padian's "Dinosau­ ceous. All members of this order were fully ria" is really just the Theropoda. Otherwise, I erect obligatory bipeds with functionally tridac- have followed Gauthier & Padian and Arcucci tyl pedes: pedal digit I was usually split or miss­ (1986, 1987) in organizing the Lagosuchia. So ing and digit V was reduced to a vestigial meta­ far, lagosuchian fossils are restricted to South tarsal, even in the most primitive forms. The America, but since they were small archosaurs, common ancestor of the theropods was almost they probably had a much wider but still un­ certainly a highly arboreal canard-wing glider known distribution. in which manual digit V was absent and digit IV was strongly reduced, perhaps to accommo­ date elongated wing feathers extending back­ ward from digit II (the longest manual digit).

Dinosaur Orders 90 Mesozoic Meanderings #2 Most large theropods were predators armed basket taxa and do not follow Linnaean syste- with obviously carnivorous dentition, but other matics beyond naming the entire group Cerato­ forms were toothless or had dentition special­ sauria. Ceratosaurians were characterized by, ized for a noncarnivorous diet. Theropods di­ among other things, a large antorbital fenestra versified into well over a score of known fami­ with no additional preantorbital fenestrae; a lies, and there were probably many more of fanglike dentary tooth that fit into a diastema which we as yet have no fossil record. Much of between and premaxilla that gave the the preceding Dinosaur Phylogeny section per­ snout a "kink" below the narial opening; crest­ tains to the Theropoda, and there is thus no ed snout; two pleurocoels in the cervical verte­ need to repeat that discussion here. brae; winglike transverse processes on the dor­ Many of the theropod families, such as the sal vertebrae; robust ; presence of as Tyrannosauridae, Dromaeosauridae, Ornitho- many as four manual digits, but with digit IV mimidae, and Oviraptoridae, are well-diag­ sometimes expressed solely as a metacarpal; nosed taxonomic units, but other families seem considerable fusion of the pelvic elements, and to have few distinguishing characters other an extra pubic fenestra situated below the ob­ than large or small size and a plesiomorphic an­ turator foramen; long, rodlike pubes with only atomical similarity among their genera that is a slight distal "foot"; metatarsal elements exhib­ difficult to characterize. This could well stem iting sporadic fusion; and distal third of the tail from the existence of a large, cryptic theropod stiffened. Most of the ceratosaurian taxa re­ tachytelic core group of small, seldom pre­ viewed by Rowe & Gauthier did not possess all served forms from which the larger, better-pre­ of those features at the same time, but they pos­ served forms evolved from time to time. Lack­ sessed enough of them that some kind of close ing strong synapomorphies with other thero­ relationship among the taxa is evident. pods, the larger species would each constitute According to Rowe & Gauthier, ceratosauri­ a small, monotypic family of its own. In this cir­ an forelimb bones, even the phalanges, were cumstance, unless the theropod fossil record hollow amd thin-walled. I cannot imagine why were to improve considerably, a satisfactory a predatory dinosaur would evolve such a char­ theropod classification would be impossible. acter, but I can easily understand how this de­ I recognize nine suborders and parasubor- velopment would improve the efficiency of a vo­ ders among the theropods, but as I have al­ lant forelimb, and was passed on to flightless ready noted more than once, their taxonomy descendants as a structural shortcoming to be will surely undergo considerable revision be­ made the best of. The pneumatization of cerato­ fore it stabilizes. saurian skeletons is, to me, strong evidence of a volant stage in their evolution. Parasuborder Ceratosauria I list six families in the Ceratosauria, includ­ The ceratosaurians are the earliest known ing the Abelisauridae and Noasauridae, which and most primitive of the "orthodox" thero­ Paul (1988b) noted as having ceratosaurian af­ pods, entering the fossil record in the Late Tri- finities, such as a large antorbital fenestra with assic (Late Carnian), continuing through the no preantorbital fenestrae and tetradactyl fore- Late Jurassic worldwide, and persisting as limbs. The Podokesauridae and Halticosauri­ abelisaurids through the Late Cretaceous in the dae are largely groups of convenience for the Gondwanian continents. smaller and larger early ceratosaurs, and future This group was diagnosed as a sister group work will either provide better diagnoses for to all other theropods (the clade ) by them or will cause them to be discarded. The Rowe & Gauthier (1990), whose classification Ceratosauridae comprises mainly the genus of the early ceratosaurians I have in part fol­ , which in some ways is a highly lowed here. The genera listed by them seem to derived ceratosaurian that is clearly different fall into three families, the Podokesauridae, from the podokesaurids and halticosaurids. Halticosauridae, and Ceratosauridae, although Finally, the Megalosauridae is included here Rowe & Gauthier regard the families as waste- following a study of the group by Britt (1991).

Parainfraclass Archosauria Cope, 1869 Dinosaur Orders The abelisaurids of South America are still ical features seldom visible in the incomplete too poorly known for any firm conclusions to material that comprises the usual type speci­ be reached concerning their taxonomy, but mens. One family, the Tyrannosauridae, consti­ some forms (such as Camotaurus) are so highly tutes a well-diagnosed clade with genera that derived postcranially that a new suborder may can be submitted to cladistic analysis (Bakker, be warranted for them. Williams & Currie, 1988), but the other fami­ I consider the Ceratosauria a parasuborder lies are more like horizontal grades whose phy- because (as noted by Paul, 1988) it was probab­ letic relationships remain obscure. Most large ly ancestral to the Spinosauria. It is also pos­ theropods are known only from scanty material sible that the carnosaurs and other tetanuran strictly classifiable as Theropoda or Carnosau­ theropods were descended from an as-yet-un­ ria incertae sedis, but I have managed to sort known form resembling Rioanibasaurus or Syn- some of the genera into six families. Some may tarsus closely enough to be classified with them. eventually turn out to be wastebasket categor­ ies, but there seems to be little else available. Suborder Spinosauria The classification given here follows Paul This new suborder comprises two families (1988b) and Molnar, Kurzanov & Dong (1990), of probable ceratosaurian descendants, the Ba- insofar as they do not contradict one another. I ryonychidae and the Spinosauridae. Paul have provisionally pigeonholed some of the (1988b) noted the resemblance of the kinked- problematic forms dealt with by Molnar (1990) snout premaxilla of podokesaurid and haltico- and Norman (1990) into the carnosaur families saurid ceratosaurians to the knoblike premaxil­ with appropriate explanatory notes when neces­ la of , and further suggested that the sary. low nasal crest of Baryonyx might be homolo­ gous to the nasal crests of Dilophosaurus. The most primitive carnosaur family is the Eustreptospondylidae. The type genus, Eustrep- Charig & Milner (1986, 1990) emphatically tospondylus, is listed by Molnar et al. (1990) as deny any relationship between the genus a probable carnosaur, and Paul (1988b) Baryonyx and the Spinosauria, but at least one grouped that genus and several others into this apomorphy— the expansion of the dentary sym­ family. The eustreptospondylids are not very physis—may place Baryonyx into this suborder. well defined, but some of their characters in­ The obvious cranial differences between Bary­ clude a moderately prominent pubic "foot," onyx and other theropods, as well as the tall, bladelike neural spines on the dorsal verte­ characters documented by Charig & Milner brae, and a straplike scapula. I classified the (1990), strongly suggest separating the family Wealden genus Becklespinax in this family by Baryonychidae into a new theropod suborder. virtue of its very tall dorsal neural spines and Study of the Spinosauridae is hampered by the conformation of its vertebral laminae, the destruction of the type material during which is similar to that in the South American World War II, but when I examined the figures genus . of Spinosaums aegyptiacus (Stromer, 1915), I noticed that the anterior dorsal vertebrae were Problems likewise beset the definition of the highly opisthocoelous, indicating that the long Allosauridae, which has only two genera that neural spines of the genus were mobile. It are at all well known: and Acrocan- would not take much dorsoventral flexion of thosaunis. Among the characters uniting these the anterior vertebral column to separate the two taxa into a family are the very prominent tips of the long spines, and "arching" the back pubic "foot," a broad squamosal-quadrate junc­ could have served a thermoregulatory and sig­ tion, and an L-shaped proximal end of meta­ naling function in the species. tarsal III (as listed by Paul). The proximal end of metatarsal III in the Valdoraptor type speci­ Suborder Carnosauria men is worn away, so I cannot tell whether it The carnosaurs were most recently de­ was L-shaped from the material available to scribed by Molnar, Kurzanov & Dong (1990), me; classifying Valdoraptor in the Allosauridae whose diagnosis includes mainly minor anatom­ is thus provisional.

Dinosaur Orders 92 Mesozoic Meanderings #2 I sympathize entirely with Paul (1988b) in structure of his new species, but the known his effort to include some small theropods in postcranial material suggests that Protoavis was the Carnosauria, because the carnosaurs were a small, arboreal canard-wing glider of the type undoubtedly descended from smaller forms. described here in the section on Dinosaur But the scarcity of complete small-theropod Phylogeny. material makes it almost impossible to find As a general rule, I have found that cranial such forms. features are very variable among the archo- Numerous apomorphies unite die tyranno- saurs, which makes them useful for diagnosing saurid carnosaurs into a single family, including taxa at or below the family level but perhaps a didactyi manus; narrow, fused nasals; serrat­ misleading for distinguishing taxa above the ed premaxillary teeth with a D-shaped cross- family level. Archosaur Baupldne tend to be section; jugal foramen; ischium deep proximal- body-conservative, so although Protoavis exhib­ ly but narrow distally, and so forth. Oddly its strong avian features in the skull, as might enough, some of these features can also be ob­ be expected in an arboreal canard-wing glider served in the small Jurassic theropod Compso- closely related to true birds, I believe it is best gnathus. It would be marvelous if future work classified as a theropod. discloses that the smallest-known theropod was close to the ancestry of the largest. I follow Suborder Coelurosauria Russell (1970), Bakker, Williams & Currie Theropods referred to the suborder Coeluro­ (1988), and Molnar, Kurzanov & Dong (1990) sauria in the past have had a disconcerting his­ in organizing this family, insofar as they do not tory of becoming something else (e.g., ornitho- contradict one another. mimids, dromaeosaurids, or troodontids) when better material was described. Gauthier (1986a, I use the parafamily Aublysodontidae (as de­ 1986b) attempted to remedy the situation by re- scribed by Molnar & Carpenter, 1989) for ty- describing the group as the clade containing rannosaurid-like theropods with D-shaped un- the Ornithomimidae plus the Maniraptora, serrated premaxillary teeth. The aublysodontids with die Maniraptora in turn being the clade of were probably ancestral to the tyrannosaurids, theropods with an avian forelimb articulation but better material is sorely needed to confirm (cf. Gauthier & Padian, 1985) — namely, the dei- this relationship. Likewise, the Dryptosauridae nonychosaurs, oviraptorosaurs, Archaeopteryx, also shows a relationship with the ty­ and birds. rannosaurids (D. Baird, pers. comm.), but the type genus needs to be fully rede- Since I exclude the birds from the Archosau- scribed. At the 1990 SVP meeting, R. Denton ria, I do not use the clade Maniraptora as a tax- (pers. comm.) displayed dryptosaurid teeth on. But I regard the known maniraptoran thero­ that lacked serrations on their mesial carinae, pods as flightless descendants of volant thero­ so I tentatively refer the tooth genus Altispinax pods in which the wing had developed a power to this family. Even if this feature were the re­ stroke and was able to fold up against the body sult of tooth-to-substrate wear in the living ani­ in an avian fashion, as described by Gauthier & mal, it might have taxonomic validity if it could Padian (1985). be shown to be present in the genera consistent- In the final analysis, I am afraid that most of the genera in the Coelurosauria are simply un- iy. diagnosable small theropods (Norman, 1990), Parasuborder Protoaviformes and that the suborder must serve as a waste- This group was created by Chatterjee (1991) basket group for such forms. Only two genera, as an avian order to accommodate his birdlike Compsognathus and , are known taxon Protoavis texenis. Like any monotypic or­ from good material. They have not yet been as­ der, it is difficult to characterize, and the range signed to any better-diagnosed theropod group, of morphological variation within the group is so I have essentially retained the Coelurosauria completely unknown. Chatterjee described in to accommodate them. great detail the specialized, highly avian cranial

Parainfraclass Archosauria Cope, 1869 93 Dinosaur Orders Suborder Ornithomimosauria rus), so it is possible that the presence of this This suborder was originally created as a character in the Dromaeosauridae and the theropod infraorder by Barsbold (1976) to com­ Troodontidae is homoplasious. More signifi­ prise the "ostrich-mimic" dinosaurs of the cant, perhaps, is the extraordinarily birdlike ar­ Early and Late Cretaceous. Largely restricted ticulation of the forelimb and manus in dromae- to North America and , the ornithomimo- osaurids (Gauthier & Padian, 1985), and the saurians were eventually subdivided into three birdlike anatomy of the skull in both dromaeo- families: Harpymimidae, Garudimimidae, Orni- saurids and troodontids. These suggest to me thomimidae, and Deinocheiridae. There is a that both families descended from volant thero- general consensus among theropod specialists pods that had developed a version of the wing- (e.g., PauL 1988b) that the monotypic families stroke of extant birds. Paul (1984, 1988b) noted Harpymimidae and Garudimimidae are a case a very close relationship between Archaeopteryx of oversplitting, and that the single family Orni- and the dromaeosaurids, and I have followed thomimidae can accommodate the genera in this suggestion in placing the Archaeopterygi- the latter two families. Other than this, I have dae in this suborder as a parafamily ancestral for the most part followed Russell (1972) and to the Dromaeosauridae. Interestingly, all of Barsbold & Osm61ska (1990) in organizing the the well-known dromaeosaurids occur consider­ Ornithomimidae. ably later than Archaeopteryx in the fossil rec­ The Deinocheiridae, however, is a monotyp­ ord; Paul's hypothesis perhaps accounts for ic family based essentially on a pair of enor­ this. mous theropod forelimbs almost 3 meters long. I have organized this suborder primarily ac­ Described as Deinocheims mirificus, the fore- cording to Ostrom (1990) and Osm61ska & limbs have confounded taxonomists ever since Barsbold (1990). their discovery. I follow Norman (1990) in ten­ Suborder Oviraptorosauria tatively including this family in the Ornithomi­ The oviraptorosaurs were a small group of mosauria. In the absence of any other deino- highly derived, birdlike maniraptoran thero- cheirid remains, it is difficult to exclude the pods known exclusively from the Late Creta­ possibility that the resemblances between Dei­ ceous of Mongolia. They seem to fall into four nocheims and other ornithomimosaurs are the families, Caenagnathidae, Elmisauridae, Ovi- result of convergence. raptoridae, and Ingeniidae, but better material Ornithomimid forelimbs were relatively may disclose that some of these families should long, entirely tridactyl with three subequal dig­ be subsumed into the others. In the best- its, and characterized by weakly developed known genera, Oviraptor and , the crests for muscular attachment. The hind skull was almost completely toothless with a limbs, on the other hand, were long, slender, strongly reduced maxilla very reminiscent of and well adapted for running. These features the condition in modern birds. Postcranially, lead me to imagine that ancestral ornithomi- however, oviraptorosaurs had a typically thero­ mids may have originated as cursorial descen­ pod anatomy. It is plain to me that these cur­ dants of a small arboreal theropod that was sorial theropods were descended from a group adapted for gliding and soaring but not pow­ of volant theropods more derived than the ar- ered flight. Nicholls & Russell (1981) found chaeopterygids. that many ornithomimid genera can be differen­ tiated by the structure of their manus. I have organized this suborder primarily ac­ cording to Barsbold, Maryanska & Osmolska Suborder Deinonychosauria (1990) and Currie (1990). This group includes most of the theropod Suborder Avimimiformes genera that developed a specialized "killer Chatterjee (1991) created this group as an claw" on their pedal digit II. Large pedal ungu­ order of primitive avians to accommodate the als are, however, known in some small thero- birdlike form portentosus from the pods outside this suborder (such as Noasau- Late Cretaceous of Mongolia. This was a near-

Dinosaur Orders 94 Mesozoic Meanderings #2 ly toothless cursorial form with large, manirap- When Russell's work is published, I will prob­ toran forelimbs that I consider to be yet ably have to move the Segnosauria back into another flightless descendant of a volant thero- the Theropodomorpha as a tenth order, but un­ pod. It does not show a close relationship with til then I provisionally retain the group within other theropods (Norman, 1990) and probably the Sauropodomorpha. does merit a suborder within the Theropoda. In elevating the Sauropodomorpha to supra- ordinal status, it was necessary to decide whether the Prosauropoda and Sauropoda SAUROPODOMORPH ORDERS themselves should each become orders. I agree that the sauropods and prosauropods together The sauropodomorphs include the enor­ form a distinctive dinosaurian order, but the mous quadrupedal, graviportal herbivores with prosauropod Bauplan is merely a variation of elongate necks and tails. As noted earlier, I do the sauropod Bauplan, and the Prosauropoda not consider them particularly closely related itself was neither diverse enough nor distinct to the theropodomorphs, because the sauropod­ enough from the Sauropoda to require more omorphs possessed a large suite of autapomor- than subordinai status. The most natural solu­ phies setting them apart from the other dino- tion was to create a single order within which saurian groups. Although they were highly de­ the prosauropods and the sauropods were sub­ rived animals, they also displayed a number of orders. This monophyletic unit I have named primitive features, such as a fully pentadactyl the Brontosauria. manus and pes, that show early evolutionary di­ vergence. In particular, sauropodomorph skele­ Order Brontosauria tons show no evidence of an arboreal stage in Brontosaurs were sauropodomorphs with their evolution, and no clear evidence that sau­ brachyiliac pelves, as opposed to the segno- ropodomorphs endured a bipedal stage, either saurs, which possessed very broad, "altiliac" (Charig, Attridge & Crompton, 196S; Charig, pelves. There were also' major differences be­ 1982). Most evidence, in fact, suggests that sau­ tween the two orders in the structure of the ropodomorphs evolved directly from as-yet-un­ skull, forelimb, and pedes. Brontosaurs pos­ known fully erect quadrupedal archosaurs. sessed five columnar metacarpals arranged in a There is also no evidence of a tachytelic sauro­ U-shaped arcade, and manual digit I was podomorph core group; their diversity from the armed with a large claw. The only known segno- Late Triassic to the Late Cretaceous can be en­ saurian forelimb is that of , tirely accounted for by the bradytelic evolution­ which is about as different from a brontosaur ary pattern common to large terrestrial verte­ forelimb as a dinosaurian forelimb could be. It brates. was tridactyl, and each digit possessed a huge claw as much as a meter long; the digits were I have very tentatively included the order not of equal length, and the humerus had a Segnosauria in the Sauropodomorpha, because very prominent deltopectoral crest. If this fore­ the segnosaurians seem like highly derived pro- limb is correctly referred to the Segnosauria, sauropods to me. Recent work by D. A. Rus­ then it weakens the argument for including the sell (pers. comm.), however, suggests instead Segnosauria within the Sauropodomorpha. that they were very highly derived theropods— as originally classified—and that their resem­ Parasuborder Prosauropoda blance to sauropodomorphs was homoplasious. The most primitive brontosaurs were the J. S. Mcintosh (pers, comm.) notes that he can prosauropods, which appeared in the fossil rec­ see no relationship between segnosaurians and ord in the Late Triassic and vanished by the sauropods, and only a slight connection if any end of the Lower Jurassic. As noted earlier, with the prosauropods. Barsbold & Maryanska prosauropods were once classified as thero­ (1990) are noncommittal about the placement pods, but this is no longer thought to be cor­ of the group, regarding it as Saurischia sedis rect. Most of the well-known prosauropod gen­ mutabilis, that is, "of changeable position." era seem to fall into an evolutionary series of

Parainfraclass Archosauria Cope, 1869 95 Dinosaur Orders larger and more graviportal forms that con­ the top of the skull. Diplodocid skulls were verge on the Sauropoda (Benton, 1990a), but long and narrow, but the narial openings were Galton (1990) has determined that the known located above the orbits. Prosauropod teeth prosauropods constitute a clade of their own, were small, numerous, and of a simple herbivo­ which diverged from the sauropod clade some­ rous design; sauropod teeth were larger, less time before the earliest known prosauropod en­ numerous, and of two derived designs: leaf- tered the fossil record. shaped and peg-shaped. Prosauropods pos­ All known prosauropods possessed a strong­ sessed elongate necks with 10 cervical verte­ ly reduced metatarsal V with at most one pha­ brae, but sauropod necks had at least 12 and lanx, even the larger forms (Melanorosauridae as many as 19 vertebrae. Sauropods had five or and Blikanasauridae). Since sauropods pos­ six sacral vertebrae, prosauropods three or sessed all five pedal digits, none of the known four. Sauropod dorsal vertebrae usually had prosauropods could have been an ancestral sau­ substantially taller neural spines than did pro­ ropod. The common ancestor of both subor­ sauropod vertebrae, and they were lightened ders, a prosauropodlike sauropodomorph with by pleurocoels, which were generally absent five robust pedal digits, has yet to be discov­ from prosauropod vertebrae. In many sauro­ ered. pod genera, the neural spines of the posterior Galton (1990) classified the prosauropods cervicals and anterior dorsals were bifurcated, into no less than seven families, some monotyp- a character that probably arose more than ic, and I have largely followed his sytem here. once as an adaptation for bearing great weight The familial differences, which encompass and, perhaps, for control of the neck. The teeth, cranial anatomy, and the structure of the shapes of the chevron bones and caudal verte­ manus and pes, seem real to me; I do not think brae are also important in sauropod classifica­ Galton has oversplit the group, although per­ tion. haps the Massospondylidae and Anchisauridae I classify the sauropods into nine families, will ultimately prove synonymous. I regard the primarily following Mcintosh (1990). One of Prosauropoda as a parasuborder, although the most primitive families, the Cetiosauridae, none of the known families would contain the seems to have been ancestral to many of the lat­ ancestral sauropod. er families, so I list it here as a parafamily. Suborder Sauropoda Order Segnosauria As one might imagine, these dinosaurs are Segnosaurs were characterized by many aut- the most difficult of all to work with, because apomorphies, especially including their very of the large size of the specimens and because distinctive "altiliac" pelvis, which was opistho- many key specimens are permanently mounted pubic and very broad in dorsal view. The for museum display. From a systematic stand­ was fused with the ischium in some genera, but point, the lack of associated skull material for was reduced in others. The ungual phalanges most of the known genera presents an acute were particularly long and laterally com­ problem that is only now being overcome. Sau­ pressed, reaching almost a meter in length in ropod taxonomies in which genera are diag­ Tliermnosaums. Although only a few genera nosed on postcranial features, such as the con­ have been described, they are so different from figurations of vertebral laminae, are in various other dinosaurs that their ordinal status is prac­ stages of development (Bonaparte, 1986b). tically beyond question, no matter which group Sauropods differed from prosauropods in they may have originated from. being generally much larger and more massive­ I recognize two families, Segnosauridae and ly built. Prosauropod skulls were long and nar­ Therizinosauridae, but the latter family is row, with narial openings situated near the tip known essentially from a very large forelimb of the snout; sauropod skulls tended to be and isolated unguals. A segnosaurlike pes has shorter and blunter, and all known skulls show also been referred to the Therizinosauridae. some movement of the narial openings toward

Dinosaur Orders 96 Mesozoic Meanderings #2 phalia and die Ornithopoda (his Euornithopo- ORNITHISCHIAN ORDERS da) were grouped into the clade . There are numerous synapomorphies uniting However, inasmuch as an incipient obturator the various groups within $6616/5 order Or- process does seem to be present in Lesothosau­ nithischia, which for the reasons noted under rus (Weishampel & Witmer, 1990a: 421; contra Dinosaur Phytogeny I retain as a dinosaurian Sereno, 1991, who nevertheless figured it as a superorder. All dinosaurologists agree that die kink in die ventral margin of the ischium in his Omithischia is monophyletic, and as I men­ Figures 9, 10), I believe that the Ornithopoda tioned previously, the only disagreements about arose separately from the other omithischians die omithischians concern details of die inter­ within die Lesothosauria. relationships of its six major subclades. These I do not employ die terms and groups present six distinctly different Bauplane Marginocephalia, despite their usage in The Di- worthy of straightforward classification into six nosauria (Weishampel, 1990; Coombs, Weis­ separate orders, namely, Lesothosauria, Anky­ hampel & Witmer, 1990a; Dodson, 1990b), be­ losauria, Stegosauria, Pachycephalosauria, Ce­ cause they are redundant with the paraorders ratopsia, and Ornithopoda. Three of the orders Ankylosauria and Pachycephalosauria. Other­ are parataxa: Lesothosauria, which I consider wise, the omithischians are classified here basal to the orders Ankylosauria, Pachycephalo­ much as they were in The Dinosauria. A plausi­ sauria, and Ornithopoda; Ankylosauria, which ble classification of the Omithischia into four is most likely ancestral to the Stegosauria; and orders (Lesothosauria, Thyreophora, Mar­ Pachycephalosauria, which is almost certainly ginocephalia, and Ornithopoda) rather than ancestral to the Ceratopsia. six, with Thyreophora divided into suborders Ankylosauria and Stegosauria, and Marginoce­ The key autapomorphy of the Omithischia is phalia into Pachycephalosauria and Ceratopsia, die opisthopubic pelvis, which was noted by was rejected as too cumbersome. Seeley (1888) when he created die order. Oth­ er splendid autapomorphies are die presence Paraorder Lesothosauria of a predentary bone, extra supraorbital ossifi­ This order is erected here for the solitary or- cations (such as a bone), and a pen­ nithischian taxon , whose key dant fourth trochanter (this may have arisen character was die lack of lateral maxillary and convergendy in some prosauropods: Cooper, mandibular emargination for cheeks. This was 1985). Sereno (1986) listed many more ornithis- plesiomorphic for the Omithischia, but the chian characters in his comprehensive cladistic presence of cheeks in all other well-known omi­ review of die group. All known omithischians thischians serves to distinguish this basal order. possessed herbivorous dentition, and the Other autapomorphies were listed by Weisham­ shapes of the teeth are genetically diagnostic. pel & Witmer (1990a) and Sereno (1991). Sereno (1986) convincingly grouped the An­ Lesothosaurus itself occurs too late (Lower kylosauria and Stegosauria into a clade previ­ Jurassic) to be ancestral to any known oraithis- ously called Thyreophora, and the Pachycepha­ chian taxa, but earlier lesothosaurians were losauria and Ceratopsia into one he named probably ancestral to basal ankylosaurians Marginocephalia. On the form of the ischium (such as ScuteUosaurus) and pachycephalosauri- (lacking an obturator process: Santa Luca, ans (such as Pisanosaurus). Cheeks may have 1980) I would further group these two clades evolved twice in the Omithischia, first in the into a larger clade, reflecting their strong dis­ Ankylosauria plus Pachycephalosauria, and tinction from the ornithopods (in which there is again in the Ornithopoda. The incipient obtura­ always a prominent obturator process), but tor process of Lesothosaurus places it closer to there is presently less need to name such the Ornithopoda than to the ankylosaurian-pa- clades dian simply to bear in mind how the or- chycephalosaurian clade. nithischian orders might be related to each oth­ Several other small omithischians known er. In Sereno's classification, the Marginoce­ from fragmentary and incomplete specimens,

Parainfraclass Archosauria Cope, 1869 97 Dinosaur Orders primarily jaws and teeth, some of which were silophodon and Thescelosaunis, but the evi­ previously classified in the family Fabrosauri- dence is weak (Galton, 1974a, 1974b; Sues & dae, are included in the order Lesotbosauria in- Norman, 1990). certae sedis. Within the Ankylosauria, neither the Nodo- Paraorder Ankylosauria sauridae nor the Ankylosauridae has any known higher-level descendant taxa (although Ankylosaurians were a major group of orni- the Ankylosauridae might be derived from as- thischians characterized by broad, low bodies yet-unknown early nodosaurids). The basal with overall dermal armor consisting of various family Scelidosauridae, however, is thought to kinds of keeled scutes, spines, and plates. They be a sister group to the order Stegosauria and originated as small scelidosaurids sometime be­ the other two ankylosaurian families, and may fore the Early Jurassic, remained in the back­ be regarded as ancestral to them. The resem­ ground of the fossil record throughout much of blance of scelidosaurid genera, such as Scelido- the Middle and Late Jurassic, and finally saurus and , to the primitive stego- emerged as important faunal elements during saurian genus is quite appar­ the Early Cretaceous, just as the stegosaurians ent and serves to confirm their common ances­ were diminishing. For many decades, the anky- try. The deep morphological differences be­ losaurian fossil record included no forms ear­ tween the later stegosaurians and the later an­ lier than Early Cretaceous (the scelidosaurids kylosaurians are what prompted me to retain were then considered stegosaurians), but dur­ the Stegosauria as a separate order instead of ing the 1980s Gallon (cf. citations in Coombs making it an ankylosaurian suborder. Other­ & Maryanska, 1990) extended their fossil rec­ wise, the Ankylosauria is organized mainly ac­ ord back to the Middle Jurassic, and it is now cording to Coombs & Maryanska, 1990. known that the ankylosaurians did not origi­ nate at the start of the Cretaceous. Order Stegosauria Nopsca (1915) suggested uniting all the ar­ Stegosaurians comprise a small monophylet- mored dinosaurs (stegosaurs, ankylosaurs, and ic order of closely related armored dinosaurs. ceratopsians) into the single group Thyreopho- They had a worldwide distribution and probab­ ra. In view of the anatomical differences ly originated sometime shortly before or during among the included forms, dinosaurologists did the Middle Jurassic, and they may have en­ not adopt Nopsca's term. Recently, however, dured as a relict group to the end of the Late the Thyreophora was revived as the smallest Cretaceous. Known forms are most numerous clade uniting all armored ornithischians, from from Middle and Late Jurassic faunas of China. the most primitive known armored form, Scutel- In stegosaurians, the dermal armor was ar­ losaums, to the stegosaurs and ankylosaurs. ranged parasagittal^ as paired spikes or thin The ceratopsians, which lacked dermal armor plates parellel to the spine. Apart from paired and belong to a different ornithischian clade, shoulder spines, caudal spikes, and occasional are, however, excluded (Sereno, 1984, 1986; regions of dermal ossicles, stegosaurians were Cooper, 1985; Gauthier, 1986a, 1986b). essentially unarmored. Ankylosaurians pos­ I conjecture that dermal armor in the Anky­ sessed dermal ossicles and keeled scutes over losauria was homologous to the parasagittal most of their bodies, ventrally as well as dorsal- dermal armor observed in most thecodontians ly in some forms. If spines were present, they and was plesiomorphic to the order Ornithis- were situated laterally along the neck and chia. Basal ankylosaurians are regarded as the shoulders; the tail possessed a club in ankylo- most primitive ornithischians above the lesotho- saurids, but otherwise it was unarmed. Stego- saurian level (Sereno, 1986), so there is indeed saurian hind limbs were generally much longer some chance that they retained the parasagittal and straighter than the front limbs, but in anky­ dermal armor of as-yet-unknown ancestral pro- losaurians, the limbs were of roughly equal terosuchians. Dermal armor may also have length. The stegosaurian pelvis possessed a been present in some ornithopods, such as Hyp- large pubis with a well-developed prepubic pro-

Dinosaur Orders 98 Mesozoic Meanderings #2 cess; the ankylosaurian pubis had a poorly de­ m61ska (1982) noted the existence of a fanglike veloped or absent prepubic process, and in lat­ premaxillary tooth in that species, and a dias­ er forms the pubis itself was highly reduced. tema at the premaxillary-maxillary junction in Later ankylosaurians possessed a broad, many pachycephalosaurs that may have accom­ splayed-out pelvis that matched their low, modated a dentary fang. Such teeth were ho­ broad bodies, but later stegosaurians possessed mologous to the maxillary and dentary fangs of tail, narrow bodies with significantly narrower Heterodontosaums. It was those observations pelves. Stegosaurian vertebrae were tall with el­ that convinced me that the heterodontosaurids evated neural spines and arches, which contrib­ had been persistently misclassified among the uted to the overall tallness and narrowness of omithopods. They should instead be thought of their bodies; ankylosaurian vertebrae had short­ as basal pachycephalosaurians in which the er neural spines and arches. Stegosaurian skulls skull had not yet developed the characteristic tended to be long and narrow, and ankylosauri­ thick bony dome. an skulls tended to be short and broad. Com­ Norman (1984) and Norman & Weishampel paring figures in Gallon (1990b) and Coombs (1985) inadvertently noted another significant & Maryanska (1990) discloses many other dif­ difference between heterodontosaurids and oth­ ferences between stegosaurian and ankylosauri­ er omithopods when they described the kinds an skeletons. of cranial kinesis found in the Ornithopoda. I follow Gallon (1990b) in retaining two fam­ Heterodontosaurids differed from all omitho­ ilies of stegosaurians, the more primitive para- pods in having had akinetic skulls; omithopods family Huayangosauridae and its descendant possessed pleurokinetic skulls as part of their family, Stegosauridae. intricate adaptations for resistant plant matter. Cranial akinesis, however, is an obvious Paraorder Pachycephalosauria character common to pachycephalosaurians The pachycephalosaurians constitute a small and ceratopsians. It further strengthens the hy­ but widespread group of ornithischians that pothesis that heterodontosaurids were basal pa­ were until recently classified as an orithopod chycephalosaurians. subgroup. Maryanska & Osmblska (1974) estab­ lished them in a separate ornithischian subor­ Weishampel & Witmer (1990b) recently re­ der, and Sereno (1986) noted their affinities viewed the Heterodontosauridae. As might be with ceratopsians and established the clade expected of any basal ornithischian group, the Marginocephalia for the two groups. heterodontosaurids were found to be similar to hypsilophodontids overall. But interestingly, One of the biggest departures of this list they noted the presence of a jugal boss in Heter­ from previous taxonomies is to include the het- odontosaums that is not known in omithopods erodontosaurids within this paraorder rather but could well be regarded as incipient to the than as the most primitive ornithopod group. prominent, hornlike jugals present in later Santa Luca (1980) described the postcranial pachycephalosaurians and ceratopsians. I be­ anatomy of Heterodontosaums, the only well- lieve that further study will disclose a suite of known heterodontosaurid, and noted that the is­ characters further increasing the gap between chium lacked an obturator process. This, he as­ heterodontosaurids and omithopods and dimin­ serted, mandated removal of the Heterodonto- ishing the gap between heterodontosaurids and sauridae from the Ornithopoda. Subsequent pachycephalosaurians. studies of the ornithischians (cf. the cladograms cited in Benton, 1990a) seem to have ignored Otherwise, my classification of the Pachy­ this observation, and the heterodontosaurids cephalosauria follows that of Maryanska continue to appear as a basal outgroup within (1990). I consider the group, with the Hetero­ the Ornithopoda in published classifications. dontosauridae included, to be a paraorder an­ cestral to the order Ceratopsia, but at present Shortly after Santa Luca's paper, the descrip­ there is no described pachycephalosaurian fam­ tion of the primitive pachycephalosaur Goyo- ily that convincingly bridges the morphological cephale lattimorei by Perle, Maryanska & Os- gap between the orders. I have included the

Parainfraclass Archosauria Cope, 1869 99 Dinosaur Orders poorly known Triassic parafamily Pisanosauri- spellings Ceratopia, Protoceratopia, and Cera- dae as the most basal pachycephalosaurians pri­ topidae are etymologically correct. In fact, call­ marily because the mandible of Pisanosaums ing the group "Ceratopsia" is as egregious as conforms to my idea of a heterodontosaurid calling the family Tyrannosauridae "Tyranno- mandible prior to the development of the aut- saurusidae," but this inapt usage has thus far apomorphic dentary fang (Weishampel & Wit- prevailed on this side of the Atlantic Ocean. mer, 1990a). Sereno (1986) clearly demonstrat­ Order Ornithopoda ed that the Homalocephalidae ("flat-headed" The ornithopods were the most diverse orni- pachycephalosaurians) were ancestral to the thischian order, comprising obligatory and fac­ Pachycephalosauridae ("dome-headed" pachy­ ultatively bipedal forms ranging from 1 to 15 or cephalosaurians), so the Homalocephalidae more meters in length. They enjoyed a world­ comprise another pachycephalosaurian para­ wide distribution from some time before the family. Finally, Chao (1983: name spelled Zhao Middle Jurassic through the end of the Late then) noted the existence of a Chinese form Cretaceous. The key autapomorphy that char­ (Chaoyoungosaurus) that some popular Chin­ acterizes the Ornithopoda is the obturator pro­ ese publications place at the base of the pachy- cess on the ischium, a character whose func­ cephalosaurian-ceratopsian divergence. Until a tion I have not been able to determine, but formal description is published, however, the which is derived within the Ornithischia. parafamily Chaoyoungosauridae is a nomen nudum. Of all the ornithischians, the ornithopods are the most-studied group, and cladograms re­ Order Ceratopsia lating its families and genera abound in the lit­ The ceratopsians, or horned dinosaurs, form erature. Most cladistic studies of the group are a well-defined monophyletic group of restrict­ in broad agreement with each other, and I ed distribution that evidently arose during the simply follow the ornithopod taxonomy present­ Early Cretaceous. It includes two parafamilies ed in The Dinosauria tSues & Norman, 1990; and one family that form an ancestor-descen­ Norman & Weishampel, 1990; Weishampel & dant series: the Psittacosauridae was ancestral Horner, 1990). As noted above, however, I to the Protoceratopsidae, which was in turn an­ have removed the Heterodontosauridae from cestral to the Ceratopsidae. Furthermore, with­ the Ornithopoda, leaving the Hypsilophodonti- in the Ceratopsidae, the parasubfamily Eucen- dae as the most primitive (para)family. Also, I trosaurinae was ancestral to the Chasmosauri- follow Horner concerning the separate origina­ nae. In this fairly straightforward progression, tion of the families Lambeosauridae and Had- the forms that lacked frill and horns (Psittaco­ rosauridae from within the parafamily Iguano- sauridae) first developed frills (Protoceratopsi­ dontidae (Horner, 1988, 1990). As he notes, dae) and then horns (Ceratopsidae). Within the postcranial anatomy of the iguanodontid the Ceratopsidae, the Eucentrosaurinae pos­ Ouranosaums is closer to that of the lambeo- sessed short frills, short, deep skulls, large na­ saurids than to that of any hadrosaurid. sal horns, and small frontal horns, which was Sereno (1986) partitioned the Ornithopoda clearly closer to the protoceratopsid condition into two major clades, the Hypsilophodontia than the long frills, long skulls, small nasal and the Iguanodontia, each of which was fur­ horns, and large frontal horns found in the ther divided into subclades. The Iguanodontia Chasmosaurinae. in particular contained a nested series of I have organized the Ceratopsia according clades five deep converging on the Hadrosauri- to Sereno (1990), Dodson & Currie (1990), dae. I have abandoned this kind of cladistic and Lehman (1990), although I have not used microtaxonomy in favor of simply listing the the clade Neoceratopsia for Protoceratopsidae families and parafamilies and their included plus Ceratopsidae. I used the American spell­ genera serially. The debate over the detailed re­ ings of the names Ceratopsia, Protoceratopsi­ lationships among the ornithopod genera is dae, and Ceratopsidae, even though the British

Dinosaur Orders 100 Mesozoic Meanderings #2 quite hearty—and for the most part beyond the archy Problem in the Taxonomic Considera­ scope of this work. tions section. The hypsilophodontids, as no­ I regard die Hypsilophodontidae as a para- ticed by several authors (e.g., Gallon, 1972), family because it is probably ancestral to the comprised a "plexus" of difficult-to-distinguish Dryosauridae, Camptosauridae, and Iguano- lineages. This impression results from their dontidae, and the Iguanodontidae as a para- somewhat tachytelic core-group role within the family because it was almost certainly ancestral Ornithopoda. to the Hadrosauridae and Lambeosauridae. The listing of hadrosaurid genera given by This is an expanion of the scope of the Hypsilo­ Weishampel & Horner (1990) notes four evolu­ phodontidae over what is given by Sues & Nor­ tionary lineages ("gryposaurs," "brachylopho- man (1990), who restrict it to the monophyletic saurs," "saurolophs," and "edmontosaurs") of clade containing only die better known genera. advanced hadrosaurids in addition to an un­ Further comments that I have on the ornitho- named basal group. I have refrained from creat­ pods may be found as notes in that section of ing subfamilies within the Hadrosauridae pend­ the table, and also in die subsections on the ing the forthcoming revision of the Hadrosauri­ Stem-Group Problem and the Too-Deep-Hier­ dae and Lambeosauridae by Horner.

Parainfraclass Archosauria Cope, 1869 101 Dinosaur Orders Notes

Dinosaur Orders 102 Mesozoic Meanderings #2 Parasuperorden Theropodomorpha nov.

Census: 4 orders, 34 families, 159 genera (42 doubtful), 221 species (80 doubtful)

Paraorden Basitheropoda nov. Census: 2 families, 3 genera, 3 species ity to Megalancosaurus, so the genus may be Family: MEGALANCOSAURIDAE nov. provisionally classified in this family. Census: 2 genera, 2 species Genus: Megalancosaurus Calzavara, Muscio & Wild, 1980 Genus: Cosesaurus Ellenberger & de Villalta, M. preonensis Calzavara, Muscio & Wild, 1974 1980 (Type) C. aviceps Ellenberger & de Villalta, 1974 (Type) NOTE: Originally classified as a thecodon- Family: LONG1SQUAMIDAE tian and thought to be a possible ancestral av­ Sharov, 1970 ian, this genus was identified as an eosuchian by Olsen (1979) and was classified as a prola- Census: 1 genus, 1 species certiform reptile by Sanz & Lopez-Martinez (1984). Molnar (1985), however, noted the pres­ Genus: Longisquama Sharov, 1970 ence of an antorbital fenestra in the type speci­ = Longisquamata McLoughlin, 1979 [sic] men as well as a general morphological similar­ L. insignis Sharov, 1970 (Type)

Order Lagosuchia Paul, 1988 Census: 2 families, 3 genera, 3 species

Family: LAGOSUCHIDAE Genus: Pseudolagosuchus Arcucci, 1987 P. major Arcucci, 1987 (Type) Bonaparte, 1975 NOTE: This genus is referred to the Stauri- kosauridae by Paul (1988). Census: 2 genera, 2 species

= Lagosuchinae Paul, 1988 Family: LAGERPETONIDAE Genus: Lagosuchus Romer, 1971 Arcucci, 1987 L. talampayensis Romer, 1971 (Type) = Lagosuchus lilloensis Romer, 1972 Census: 1 genus, 1 species Genus: Romer, 1971

Parainfraclass Archosauria Cope, 1869 103 Theropodomorpha nov. L. chanarensis Romer, 1971 (Type) similar to a small dinosaur"; cf. New Mexico = Lagerpeton canarensis Paul, 1988 [sic] Museum of Natural History publication Timetracks 5(4): p. 4] Genus: [To be described from the Upper Trias- sic of New Mexico: a new kind of "thecodont

Orden Herrerasauria Gaiton, 1985 Census: 2 families, 8 genera (1 doubtful), 8 species (1 doubtful)

Family: STAURIKOSAURIDAE Family: HERRERASAURIDAE Gaiton, 1977 Benedetto, 1973

Census: 3 genera (1 doubtful), Census: 3 genera, 3 species 3 species (1 doubtful) = Herrarasauridae Gauthier & Padian, Genus: "" Murry & Long, 1989 1985 [sic] [to be described; listed in several articles in Dawn of the Age of Dinosaurs in the American Genus: Herrerasaurus Reig, 1963 Southwest, S. G. Lucas & A. P. Hunt, eds., = Herrarasaurs Gauthier, 1986 [sic] 1989] = Herrarasaurus Gauthier & Padian, 1985 = Chindesaurus [Anonymous] 1985 [nomen [sic] nudum, in Science News 727(21): 325, May H. ischigualastensis Reig, 1963 (Type) 25,1985] Genus: Ischisaurus Reig, 1963 "C. bryansmalli" Murry & Long, 1989 [to be /. cattoi Reig, 1963 (Type) described] Genus: Young, 1948 = Chindesaurus smalli [Anonymous] 1985 S. triassicus Young, 1948 (Type) [nomen nudum, in San Diego Union, June 2,1985] NOTE: The type specimen of this species (a left maxilla with teeth and associated frag­ Genus: Frenguellisaurus Novas, 1986 ments) may belong to a herrerasaurid, but post- F. ischigualastensis Novas, 1986 (Type) cranial material referred to this species is pro- NOTE: This genus, originally described as a sauropod (Rozhdestvensky, 1965; Charig, At- primitive theropod, may be a staurikosaurid tridge & Crompton, 1965; van Heerden 1975, (Molnar, 1990). It is classified in the Her- 1980). Norman (1990) lists it as a nomen du­ rerasauridae in Paul, 1988. Referred to this bium, Theropoda incertae sedis. P. J. Currie family provisionally. (pers. comm.) suggests it may be a ceratosaur. Classified in this family provisionally. Genus: von Huene, 1942 [nomen dubium] = Spondylosma Hunt, 1991 [sic] S. absconditum von Huene, 1942 (Type) HERRERASAURIA incertae sedis NOTE: This genus, originally described as a primitive saurischian, may be a staurikosaurid. Census: 2 genera, 2 species Listed as Dinosauria incertae sedis by Sues Genus: Aliwalia Gaiton, 1985 (1990); referred to this family provisionally. A. rex Gallon, 1985 (Type) Genus: Colbert, 1970 NOTE: Listed as Dinosauria incertae sedis = Starikosaurus Parrish, 1989 [sic] by Sues (1990). S. pricei Colbert, 1970 (Type)

Theropodomorpha nov. 104 Mesozoic Meanderings #2 Genus: Walkeria Chatterjee, 1986 the Herrerasauridae in Paul, 1988 and as a her- W. maleriensis Chatterjee, 1986 (Type) rerasaurian in Novas, 1989. Listed as Theropo- NOTE: Initially described as a podokesau- da incertae sedis by Norman (1990). rid theropod, the above genus is classified in

Paraorder: Theropoda Marsh, 1881 Census: 9 suborders, 28 families, 145 genera (41 doubtful), 207 species (79 doubtful) Parasuborden Ceratosauria Marsh, 1884 Census: 6 families, 41 genera (12 doubtful), 61 species (28 doubtful)

Family: PODOKESAURIDAE so the synonymy between the two taxa is only von Huene, 1914 subjective. See also note for Rioarribasaurus. Genus: Talbot, 1911 Census: 6 genera (2 doubtful), P. holyokensis Talbot, 1911 (Type) 8 species (3 doubtful) = holyokensis (Talbot, 1911)

= Paul, 1988 Genus: Rioarribasaurus Hunt & Lucas, 1991 = Coelophysinae Nopcsa, 1928 R. colberti Hunt & Lucas, 1991 (Type) = Podokesaurinae Nopcsa, 1923 NOTE: This genus and species were pro­ = Segisauridae Camp, 1936 posed for the Ghost Ranch theropods previous­ ly referred to Coelophysis. Hunt & Lucas Genus: Coelophysis Cope, 1889 [nomen dubium (1991) regard Coelophysis bauri and Longosau­ in Hunt & Lucas, 1991] rus longicollis as nomina dubia based on inade­ = Coelophyses Stokes, 1988 [sic] quate or incorrectly identified material and so C bauri (Cope, 1887) (Type) unsuitable as names for the Ghost Ranch thero­ = bauri Cope, 1887 [nomen pods. dubium] = Tanystrophaeus bauri (Cope, 1887) Genus: Camp, 1936 [nomen dubium] S. halli Camp, 1936 (Type) C. willistoni (Cope, 1887) [nomen dubium] Genus: Syntarsus Raath, 1969 = Tanystrophaeus willistoni Cope, 1887 5. rhodesiensis Raath, 1969 (Type) [nomen dubium] = Coelophysis rhodesiensis (Raath, 1969) NOTE: See note for Rioarribasaurus. 5. kayentakatae Rowe, 1989 Genus: Longosaurus Welles, 1984 [nomen Genus: [To be described from the Rutiodon dubium in Hunt & Lucas, 1991] zunii zone of the lower portion of the L. longicollis Welles, 1984 (Type) Petrified Forest Member of the Chinle Forma­ = Coelurus longicollis Cope, 1887 [nomen tion of Arizona; R. A. Long, pers. comm.] dubium] = Coelophysis longicollis (Cope, 1887) Genus: [To be described from the Ghost [nomen dubium] Ranch quarry: a theropod with a skull resem­ = Tanystrophaeus longicollis (Cope, 1887) bling that of Rioarribasaurus but possessing a [nomen dubium] prominent sagittal crest; specimen presently = Coelophysis collis Haughton, 1932 [sic] housed at the Carnegie Museum; R. A. Long, NOTE: Hunt & Lucas, 1991 indicate that pers. comm.] the type specimen of Longosaurus longicollis is not part of the lectotype of Coelurus longicollis,

Parainfraclass Archosauria Cope, 1869 105 Theropodomorpha nov. Genus: [To be described from the Chinle For­ Genus: Lilienstemus Welles, 1984 mation near Lacey Point, Petrified Forest; L. lilienstemi (von Huene, 1934) (Type) UCMP specimen 129618, similar to but differ­ = Halticosaurus lilienstemi von Huene, ing in anatomical details from Rioarribasau- 1934 ms; Padian, 1986; Hunt & Lucas, 1991] Genus: Tanystrosuchus Kuhn, 1963 [nomen Genus: [To be described; a "small ceratosaur" dubium; = Halticosaurus or Lilienstemus?] from the Lower Chinle Formation; Murry & T. posthumus (von Huene, 1908) (Type) Long, 1989; Colbert, 1989] = Tanystrophaeus posthumus von Huene, 1908 [nomen dubium] - Coeiophysis posthumus (von Huene, Family: HALT1COSAURIDAE 1908) [nomen dubium] von Huene, 1956 NOTE: Wild (1973) removed this species from synonymy with conspicuus, Census: 6 genera (3 doubtful), where it was previously classified. Kuhn (1963) 7 species (3 doubtful) created a separate generic name for the spe­ cies after deciding that it is not referable to the = Hatticosaurinae Paul, 1988 genus Tanystropheus, and also (1965) noted that the species might be protorosaund and Genus: Dandakosaums Yadagiri, 1982? not dinosaurian. Steel (1970) noted that the D. indicus Yadagiri, 1982? (Type) species might be referable to the genus Haltico­ NOTE: This is one of two "carnosaurs" re­ saurus. Listed as Theropoda incertae sedis by ported by Yadagiri (1979) from the Kota For­ Norman (1990). mation of India. Reference not yet seen, so year is uncertain, but the genus and species are Genus: [To be described; a "large ceratosaur" reported as having "certain similarities with Si- from the Lower Chinle Formation; Parrish & nosaurus triassicus" in Geological Survey of In­ Carpenter, 1986] dia Annual General Report for 1982-83, 117 (1990): 223. Provisionally classified as a haltico- Genus: [To be described; a double-crested saurid, pending receipt of a copy of the paper Lower Jurassic theropod from Kunming, Yun­ that explains just which parts of the composite nan, China illustrated in Asahi Shinbun May Sinosaurus triassicus this genus is similar to. 29,1989; M. Tanimoto, pers. comm.; similar to Dilophosaurus: P. Currie, pers. comm.] Genus: Dilophosaurus Welles, 1970 D. wetherilli (Welles, 1970) (Type) Genus: [To be described from Airel, Norman­ = Megalosaurus wetherilli Welles, 1970 dy, originally referred to Halticosaurus sp. in [New large species to be described; Welles, Larsonneur & Lapparent, 1966; presently 1984] being restudied as a possible new genus by G. Cuny and P. M. Galton; Buffetaut, Cuny & Genus: Dolichosuchus von Huene, 1932 [no- Le Loeuff, 1991] men dubium; = Halticosaurus or Lilienster- nusl] D. cristatus von Huene, 1932 (Type) Family: CERATOSAURIDAE NOTE: Listed as Theropoda incertae sedis Marsh, 1884 emend. Gilmore, 1920 by Norman (1990). Genus: Halticosaurus von Huene, 1908 [nomen Census: 2 genera, 4 species (2 doubtful) dubium] Genus: Ceratosaurus Marsh, 1884 H. longotarsus von Huene, 1908 (Type) C nasicomis Marsh, 1884 (Type) ?H. orbitoangulatus von Huene, 1932 = Megalosaurus nasicomis (Marsh, 1884) = Labrosaurus sulcatus Marsh, 1896 [nomen dubium]

Theropodomorpha nov. 106 Mesozoic Meanderings #2 = Ceratosaurus nasicomus Chabli, 1985 saundae is here included in the suborder Cerat- [sic] osauria. ?C. ingens (Janensch, 1920) [nomen dubium] Genus: Embasaurus Riabinin, 1931 [nomen = Megalosaurus ingens Janensch, 1920 dubium] [nomen dubium] - Embasasaurus Carroll, 1987 [sic] ?C. roechlingi Janensch, 192S [nomen E. minax Riabinin, 1931 (Type) dubium] = Labrosaurus stechowi Janensch, 192S Genus: Erectopus von Huene, 1922 [nomen dubium] E. sauvagei von Huene, 1932 (Type) = steschowi Chabli, 1985 [sic] = Megalosaurus superbus Sauvage, 1882 = Ceratosaurus roechlinqi Chabli, 1985 [sic] (in part) [New large species to be described by Mad- = Erectopus superbus (Sauvage, 1882) sen & Welles from the Cleveland-Lloyd NOTE: The above genus may be an abelisau- Quarry in Utah; Madsen, 1978] rid or may belong in its own family (R. E. Mol- nar, pers. comm.; Molnar, 1990; Buffetaut, Cu- Genus: Andrews, 1921 ny & Le Loeuff, 1991). The collection that in­ = Sacrosaurus Glut, 1972 [sic] cludes the type specimens is apparently lost. S. woodi Andrews, 1921 (Type) = Magnosaurus woodwardi von Huene, Genus: Kaijiangosaurus He, 1984 1932 K. lini He, 1984 (Type) Genus: Dong, 1973 [nomen dubium] Family: MEGALOSAURIDAE = Kelmaysaurus Dong, 1987 [sic] Huxley, 1869 K. petrolicus Dong, 1973 {Type) Census: 11 genera (2 doubtful), Genus: Magnosaurus von Huene, 1932 26 species (15 doubtful) M. nethercombensis (von Huene, 1926) (Type) = Erectopodidae von Huene, 1932 = Megalosaurus nethercombensis von = lliosuchidae Paul, 1988 Huene, 1926 = Megalosauri Fitzinger, 1843 ?M. lydekkeri (von Huene, 1926) [nomen = Megalosaurinae Paul, 1988 dubium] = Megalosauroides Gervais, 1853 - Megalosaurus lydekkeri von Huene, 1926 = Torovosauridae Kurzanov, 1989 [sic] [nomen dubium] - Torvosauridae Jensen, 1985 NOTE: This family has become a "grab- Genus: Megalosaurus Buckland, 1824 bag" for large theropod genera based on frag­ = Gressylosaurus Lapparent, 1967 [sic, for mentary remains. British megalosaurids are cur­ Gressfyosaurus Riitimeyer, 1857] rently being restudied by S. P. Welles & H. P. = Megalosaurus von Huene, 1926 [sic] Powell, and continental European megalosau­ = Megalosaums von Huene, 1926 [sic] rids are being restudied by P. Taquet & H. P. = Megalosaurus Parkinson, 1822 [nomen Powell (manuscripts in preparation). These nudum] studies should greatly aid the classification of = Megalosausus von Huene, 1926 [sic] many problematic large-dieropod taxa. Mean­ = Megalousaurus Ameghino, 1913 [sic] while, Britt (1991) has recently restudied the = Megolosaurus von Huene, 1926 [sic] genus and other theropods from = Meqalosaurus Walker, 1964 [sic] the and has concluded = Scrotum Brookes, 1763 [nomen oblitum] that the Megalosaundae are probably derived M. bucklandii Ritgen, 1826 (Type) ceratosaurians (sensu Gauthier, 1986). Follow­ = Megalosaurus bucklandi Mantell, 1827 ing Britt's recommendation, the family Megalo­ [sic]

Parainfraclass Archosauria Cope, 1869 107 Theropodomorpha nov. = Scrotum humanum Brookes, 1763 NOTE: Buffetaut, Cuny & Le Loeuff (1991) [nomen oblitum] consider this species to be based on parasuchi- - MegaJosaurus conybearei Ritgen, 1826 an teeth, the only post-Triassic record of a pa- [nomen oblitum] rasuchian. ?M. cloacinus Quenstedt, 1858 [nomen M. andrewsi (von Huene, 1932) dubium] = Sarcosaurus andrewsi von Huene, 1932 = Gressfyosaurus cloacinus (Quenstedt, ?M. pombali de Lapparent & Zbyszewski, 1858) [nomen dubium] 1957 [nomen dubium] = cloacinus (Quenstedt, ?M. inexpectatus del Corro, 1966 [nomen 1858) [nomen dubium] dubium] NOTE: The above species is probably based ?M. chubutensis del Corro, 1974 [nomen on rauisuchian teeth (Benton, 1986). dubium] ?M. insignis Eudes-Deslongchamps & Len- ?M. tibetensisZhao , 1986 [nomen nudum] nier vide Lennier, 1870 [nomen dubium] ?M. dapukaensis Zhao, 1986 [nomen nudum] = Erectopus insignis (Eudes-Deslong­ [New species to be described by S. P. champs & Lennier vide Lennier, 1870) Welles & H. P. Powell] [nomen dubium] Genus: Piveteausaurus Taquet & Welles, 1977 = Morosaurus marchei Sauvage, 1897/8 P. divesensis (Walker, 1964) (Type) [nomen dubium] = divesensis Walker, NOTE: A tooth referred to Morosaurus mar­ 1964 chei in Sauvage, 1897/8 is indeed a sauropod = divesensis (Walker, tooth, but the type specimen, a caudal cen­ 1964) trum, is apparently referable to Megalosaurus insignis (de Lapparent & Zbyszewski, 1957). Genus: Eudes-Deslongchamps, ?M. obtusus Henry, 1876 [nomen dubium] 1838 = Plateosaurus obtusus (Henry, 1876) = Peukxlopleuron Stromer, 1934 [sic] [nomen dubium] = Poecilopleuron Bronn, 1837 [nomen NOTE: The above species is probably based nudum] on rauisuchian teeth (Benton, 1986). = Poecilopleuron Fitzinger, 1843 [sic] ?M. pannoniensis Seeley, 1881 [nomen = Poecilopleurum Agassiz, 1846 [sic] dubium] = Poekilipleuron Kuhn, 1965 [sic] = Megalosaurus pannonicus von Huene, = Poelicopleurum Kuhn, 1965 [sic] 1926 [sic] = Poikilopleuron Owen, 1841 [sic] = Gen. indet. pannonicus Huene, 1932 P. bucklandii Eudes-Deslongchamps, 1838 [sic] (Type) ?M. superbus Sauvage, 1882 [nomen dubium; = Poecilopleuron bucklandi (Eudes-Des­ in part — see also Erectopus] longchamps, 1838) ?M. cambrensis (Newton, 1899) [nomen = Poecilopleurum bucklandi (Eudes-Des­ dubium] longchamps, 1838) = Zanclodon cambrensis Newton, 1899 = Poikilopleuron bucklandi (Eudes-Des­ [nomen dubium] longchamps, 1838) = Gressfyosaurus cambrensis (Newton, = gallicus Cope, 1867 1899) [nomen dubium] = Dryptosaurus gallicus (Cope, 1867) ?M. hungaricus Nopcsa, 1902 [nomen = Poecilopleurum gallicum (Cope, 1867) dubium] = Megalosaurus poikilopleuron von ?M. terquemi von Huene, 1926 [nomen Huene, 1923 dubium] ?P. schmidti Kiprijanov, 1883 [nomen = Gressylosaurus terquemi (von Huene, dubium] 1962) Lapparent, 1967 [sic] = Megalosaurus schmidti (Kiprijanov, 1883) [nomen dubium]

Theropodomorpha nov. 108 Mesozoic Meanderinqs #2 NOTE: The above species may be a cerato- Genus: Abelisaurus Bonaparte & Novas, 1985 saurid, but is probably indeterminate (R. E. A. comahuensis Bonaparte & Novas, 1985 Molnar, pers. comm.). (Type) Genus: Torvosaums Galton & Jensen, 1979 Genus: Camotaurus Bonaparte, 1985 = Torovosaurus Kurzanov, 1989 [sic] = Camotosaurus Kricher, 1990 [sic] T. tanneri Galton & Jensen, 1979 (Type) C. sastrei Bonaparte, 1985 (Type) = Megalosaurus tanneri (Galton & Jensen, Genus: Genyodectes Woodward, 1901 [nomen 1979) dubium] Genus: Unquillosaurus J. Powell, 1979 = Geniodectes Bonaparte, Novas & Coria, U. ceibalii J. Powell, 1979 (Type) 1990 [sic] = Unquillosaurus ceibalensis Stipanicic & => Genyodetes Ameghino, 1913 [sic] Bonaparte, 1979 [sic] G. serus Woodward, 1901 (Type) NOTE: The above genus is referred to this Genus: Dong, 1984 family provisionally. R. E. Molnar believes it is = Xuanhangosaurus Haubold, 1990 [sic] not an abelisaurid (pers. comm.), Bonaparte, = Xuanhonosaurus Dong & Tang, 1985 [sic] Novas & Coria (1990) consider it indetermi­ X. qilixiaensis Dong, 1984 (Type) nate. = Xuanhanosaurus qiladaenensis Dong, 1987 [sic] Genus: Indosaurus von Huene, 1932 = Xuanhonosaurus qilbdan Kurzanov, /. matleyi von Huene, 1932 (Type) 1989 [sic] = Megalosaurus matleyi (von Huene, 1932) NOTE: The above genus is considered a Genus: [To be described by S. P. Welles & H. probable abelisaurid by Molnar (1990) but not P. Powell] by Bonaparte, Novas & Coria (1990). [Type species to be described] = Megalosaurus hesperis Waldman, 1974 Genus: von Huene, 1932 = Megalosaurus bucklandi von Meyer, /. raptorius von Huene, 1932 (Type) 1883 non Ritgen, 1826 NOTE: The above genus is considered a probable abelisaurid by Molnar, 1990 and Bo­ Genus: [To be described by S. P. Welles & H. naparte, Novas & Coria, 1990. P. Powell, based on the lectotype knee joint of harrisoni; the generic name Genus: Labocania Molnar, 1974 Scelidosaurus is to be conserved for the L. anomala Molnar, 1974 (Type) ankyiosaurian; R. A. Long, pers. comm.] NOTE: The above genus is referred to this family provisionally (G. Leahy, pers. comm.). Genus: [To be described from the Kota Forma­ tion of India; Yadagiri, 1979] Genus: Lavocat, 1955 M. crenatissimus (Deperet, 1896) (Type) Genus: [To be described by D. B. Norman, D. = Megalosaurus crenatissimus Deperet, B. Weishampel and D. Grigorescu; a new 1896 large theropod from Romania; Grigorescu, NOTE: The above genus is considered a Seclamen, Norman & Weishampel, 1990] possible abelisaurid by Molnar (1990). Genus: Le Loeuff & Buffetaut, Family: ABELISAURIDAE 1991 Bonaparte & Novas, 1985 T. salluvicus Le Loeuff & Buffetaut, 1991 (Type) Census: 9 genera (1 doubtful), Genus: Martinez, Gimenez, 9 species (1 doubtful) Rodriguez & Bochatey, 1986 = Abelisaurinae Paul, 1988 X. bonapartei Martinez, Gimenez, Rodriguez & Bochatey, 1986 (Type)

Parainfraclass Archosauria Cope, 1869 109 Theropodomorpha nov. Genus: Lukousaurus Young, 1948 Family: NOASAURIDAE = Loukousaurus Romer, 1966 [sic] Bonaparte & J. Powell, 1980 = Lucousaurus Rozhdestvensky, 1977 [sic] = Lukosaurus Camp, Welles & Green, 1953 Census: 1 genus, 1 species [sic] = Noasaurinae Paul, 1988 L. yini Young, 1948 (Type) Genus: Noasaurus Bonaparte & J. Powell, 1980 Genus: Procompsognathus E. Fraas, 1913 N. leaii Bonaparte & J. Powell, 1980 (Type) P. triassicus E. Fraas, 1913 (Type) Genus: Pterospondylus Jaekel, 1913 [nomen dubium; = Procompsognathus7] CERATOSAURIA incertae sedis P. trielbae Jaekel, 1913 (Type)

Census: 6 genera (4 doubtful), Genus: von Huene, 1910 [nomen dubium] 6 species (4 doubtful) S. elginensis von Huene, 1910 (Type) = Procompsognathidae von Huene, 1929 Genus: Velocipes von Huene, 1932 [nomen = Procompsognathinae Nopcsa, 1923 dubium] Genus: Avipes von Huene, 1932 [nomen V. guerichi von Huene, 1932 (Type) dubium] = Velocipes gurichi von Huene, 1932* A. dillstedtianus von Huene, 1932 (Type)

Suborder Spinosauria nov.

Census: 2 familes, 3 genera, 3 species

Family: BARYONYCHIDAE Family: SPINOSAURIDAE Stromer, 1915 Charig & Milner, 1986 Census: 2 genera, 2 species Census: 1 genus, 1 species Genus: Siamosaurus Buffetaut & Ingavat, 1986 Genus: Baryonyx Charig & Milner, 1986 5. suteethomi Buffetaut & Ingavat, 1986 B. walked Charig & Milner, 1986 (Type) (Type) NOTE: The above genus (and family) is re­ NOTE: The above genus is referred to this ferred to this suborder provisionally, based on family provisionally. the near identity of the premaxilla of Baryonyx with material referred to Spinosaurus by Ta- Genus: Spinosaurus Stromer, 1915 quet, 1984 and on the similarity of the den- S. aegyptiacus Stromer, 1915 (Type) taries of the two genera. It should be noted [Species noted as Spinosaurus B in Stromer, that Charig & Milner (1986, 1990) maintain 1934; specimens destroyed in 1944 during that Baryonyx shows no clear relationship with a World War II bombing raid, so it is un­ Spinosaurus and argue for its placement else­ likely that this species will ever be formally where within die Theropoda. described] [Possible new species to be described from Niger, Algeria, and Morocco, noted by Ta- quet, 1984]

Theropodomorpha nov. 110 Mesozoic Meanderings #2 Suborder: Carnosauria von Huene, 1920 Census: 6 families, 38 genera (10 doubtful), 56 species (19 doubtful) Genus: Dong, Chang, Li & Parafamily: EUSTREPTOSPONDYLIDAE Zhou, 1978 Paul, 1988 = Youngchuanosaurus Zhao, 1986 [sic] = Yuongchuonosaurus Buffetaut & Census: 7 genera, 8 species Suteethorn, 1989 [sic] = Eustreptospondyiinae Paul, 1988 = Yungchuanosaurus Dong, 1979 [sic] = lliosuchidae Paul, 1988 Y. shangyouensis Dong, Chang, Li & Zhou, = Metriacanthosaurinae Paul, 1988 1978 (Type) = shangyouensis Genus: Becklespinax nov. (Dong, Chang, Li & Zhou, 1978) B. altispinax (Paul, 1988) (Type) = Yangchuanosaurus shangyouensis Dong, = Acrocanthosaurus altispinax Paul, 1988 Chang, Li & Zhou, 1978 [sic] NOTE: Type specimen of the above species = Yangchuanosaurus shangyuensis Dong, is BMNH R1828, a series of three caudal dor­ 1987 [sic] sal vertebrae with very tall neural spines from = Yangchuanosaurus shanguyensis Kur­ the Lower Wealden of Battle-near-Hastings, zanov, 1989 [sic] East Sussex. These vertebrae are the source of - Yangchuanosaurus shanyuensis Kur­ the name Altispinax von Huene, 1923. zanov, 1989 [sic] Genus: Eustreptospondylus Walker, 1964 Y. magnus Dong, Zhou & Zhang, 1983 E. oxoniensis Walker, 1964 (Type) = Yangchuanosaurus magnum Dong, 1980 = Streptospondylus cuvieri Owen, 1842 [nomen nudum] = Megalosaunts cuvieri (Owen, 1842) = Yangchuanosaurus maganus Dong, [New species to be described by S. P. Welles Zhou & Zhang 1983 [sic] & H. P. Powell; R. A. Long, pers. comm.] Genera: [To be described; as many as five new Genus: Dong, 1985 theropods, known from five distinctive humeri G. constmctus Dong, 1985 (Type) from Colorado; Jensen, 1985] Genus: von Huene, 1932 /. incognitos von Huene, 1932 (Type) Family: ALLOSAURIDAE Marsh, 1878 = Megalosaums incognitos (von Huene, 1932) Census: 11 genera (4 doubtful), Genus: "Kagasaurus" [a large theropod from 18 species (8 doubtful) Japan; Hisa, 1988, Utan Scientific Magazine = Allosaurinae Paul, 1988 #4, p. 24; to be described] = Antrodemidae Stromer, 1934 Genus: Metriacanthosaurus Walker, 1964 a Bahariasauridae von Huene, 1948 = Metricanthosaums Swinton, 1970 [sic] = Bahartsauridae Maleev, 1968 [sic] M. parked (von Huene, 1926) (Type) = Stromer, 1931 = Megalosaums parkeri von Huene, 1926 = Labrosauridae Marsh, 1882 = Streptospondilidae Kurzanov, 1989 [sic] Genus: "Mifunesaurus" [a large theropod from = Streptospondylidae Kurzanov, 1989 Japan; Hisa, 1988, Utan Scientific Magazine #4, p. 24; to be described] Genus: Acrocanthosaurus Stovall & Langston, 1950 Genus: Piatnitzkysaurus Bonaparte, 1979 = Arcocanthosaurus Stovall & Langston, = Piatnitzkisawus Kurzanov, 1989 [sic] 1950 [sic] P. fioresi Bonaparte, 1979 (Type)

Parainf raciass Archosauria Cope, 1869 111 Theropodomorpha nov. = Arcocantosaurus Bonaparte, 1978 [sic] [New species to be described from the Mor­ A. atokensis Stovall & Langston, 1950 (Type) rison Formation by R. T. Bakker] Genus: Aliosaurus Marsh, 1877 Genus: Antrodemus Leidy, 1870 [nomen dubi­ = Apatodon Marsh, 1877 [nomen dubium] um; = AUosaums?] = Creosaurus Marsh, 1878 - Anthrodemus von Huene, 1926 [sic] = Empaterius White, 1973 [sic] - Antrodesmus Mook, 1916 [sic] = Epanterias Cope, 1878 = Poicilopleuron Leidy, 1870 [sic; for = Epantherias Romer, 1966 [sic] Poekilopleuron Eudes-Deslongchamps, = Labradosaums Bonaparte, 1978 [sic] 1838] = Labrosaums Marsh, 1879 A. valens (Leidy, 1870) (Type) = Laerosaums Glut, 1972 [sic] = Poicilopleuron valens Leidy, 1870 ?A. meriani (Greppin, 1870) [nomen dubium] [nomen dubium] = Megalosaums meriani Greppin, 1870 = AUosaums valens (Leidy, 1870) [nomen [nomen dubium] dubium] = Antrodemus meriani (Greppin, 1870) NOTE: This genus is probably a senior syno­ [nomen dubium] nym of AUosaums, but it is best left isolated = Labrosaums meriani (Greppin, 1870) until comparative work on all the Morrison al- [nomen dubium] losaurid specimens is completed. A. fragilis Marsh, 1877 (Type) Genus: Bahariasaurus Stromer, 1934 = Labrosaums fragilis (Marsh, 1877) B. ingens Stromer, 1934 (Type) = Apatodon mints Marsh, 1877 [nomen NOTE: This genus is referred to this family dubium] provisionally. = AUosaums lucaris Marsh, 1878 = Antrodemus lucaris (Marsh, 1878) Genus: Stromer, 1931 = Labrosaums lucaris (Marsh, 1878) = Carcharodonsaurus Romer, 1966 [sic] = Creosaurus atrox Marsh, 1878 - Carchrodontosaums White, 1973 [sic] = AUosaums atrox (Marsh, 1878) C. saharicus (Deperet & Savornin, 1925) = Antrodemus atrox (Marsh, 1878) (Type) = Camptonotus amplus Marsh, 1879 = Megalosaums saharicus Deperet & = Camptosaums amplus (Marsh, 1879) Savornin, 1925 = Labrosaums ferox Marsh, 1884 = Megalosaums (Dryptosaums) saharicus (provisionally) (Deperet & Savornin, 1925) = AUosaums ferox (Marsh, 1884) = Megalosaums africanus von Huene, 1956 (provisionally) NOTE: The above genus is referred to this = AUosaums agilis ZitteL 1887 [sic] family provisionally. - AUosaums ferox Marsh, 1896/(Marsh, Genus: Hu, 1964 1884) [sic] = Chilantaiosaums Romer, 1966 [sic] - Labrosaums fragilis Marsh, 18% [sic] = Chilanthiosaums Glut, 1972 [sic] = AUosaums gracilis von Huene, 1929 [sic] = Chlilantaisaurus Dong, 1980 [sic] ?A. amplexus (Cope, 1878) ?C sibiricus (Riabinin, 1914) Molnar, 1990 = Epanterias amplexus Cope, 1878 [nomen dubium] ?A. tendagurensis Janensch, 1925 [nomen = AUosaums sibiricus Riabinin, 1914 dubium] [nomen dubium] = Antrodemus tendagurensis (Janensch, = Antrodemus sibiricus (Riabinin, 1914) 1925) [nomen dubium] [nomen dubium] [New small species to be described from the C. tashuikouensis Hu, 1964 (Type) Morrison Formation by J. Madsen and S. C. maortuensis Hu, 1964 P. Welles]

Theropodomorpha nov. 112 Mesozoic Meanderings #2 Genus: Compsosuchus von Huene, 1932 ignated. The generic name is, however, preoc­ [nomen dubium] cupied (R. E. Molnar, pers. comm.), while the C. solus von Huene, 1932 (Type) species may be referable to Allosaurus (R. A. NOTE: The above genus, usually classified Long, pers. comm.), perhaps to the species Al­ as a coelurid, is probably an allosaurid (Mol- losaurus amplexus (as in Paul, 1988). nar, 1990). Genus: Streptospondylus von Meyer, 1830 Genus: "Futabasaurus" Lambert, 1990 [a large S. altdorfensis von Meyer, 1832 (Type) ?carnosaur to be described from Japan] NOTE: The above genus, often classified as crocodilian, is definitely a theropod (S. Picker­ Genus: "Jiangjunmiaosaurus" [Anonymous] ing, pers. comm.), probably allosaurid. Other 1987 [a large, primitive allosaurid to be de­ species referred to this genus are crocodilian scribed in 1992 from a nearly complete skele­ and are not listed here. ton discovered in 1987 by the Canada-China Dinosaur Project; Dong Z., pers. comm.; D. Genus: Szechuanosaurus Young, 1942 [nomen Lambert, pers. comm.; Currie, 1991 SVP an­ dubium] nual meeting abstracts; see also "Monolopho- = Szechaunosaurus Dong, 1979 [sic] saurus"] = Szechusanosaurus Romer, 1966 [sic] S. campi Young, 1942 (Type) Genus: "Katsuyamasaurus" Lambert, 1990 [a = Metriacanthosaurus carpenteri Paul, 1988 large ?carnosaur to be described from Japan] [sic] Genus: "Madsenius" Lambert, 1990 [to be S. yandonensis Dong, Chang, Li & Zhou, described from the Morrison Formation by R. 1978 [nomen nudum] T. Bakker; based on distinctive skull material Genus: Valdoraptor nov. and other remains previously referred to Al- V. oweni (Lydekker, 1889) (Type) losaums and Creosaurus] = Megalosaurus oweni Lydekker, 1889 Genus: "" Lambert, 1990 [to = Altispinax oweni (Lydekker, 1889) be described in 1992; a crested ?allosaurid = Altipinax oweni von Huene, 1932 [sic] from China previously referred to in New Sci­ NOTE: Type specimen of the above species entist, November 12, 1987: 28, 29 and is BMNH R2559, a partial left metatarsus from Report, January 4,1988: 28-32 as "Jiangjun­ the Upper Wealden of Cuckfield, West Sussex, miaosaurus"; Dong Z., pers. comm.; P. J. Cur­ originally described by Owen (1857) as a Hylae- rie, pers. comm.] osaurus metapodium. Referred to this family provisionally. Genus: Omithomimoides von Huene, 1932 [no- men dubium] Genus: [To be described from the Wealden O. mobilis von Huene, 1932 (Type) Formation of the ; Hutt, Sim- O. barasimlensis von Huene, 1932 [nomen monds & Hullman, 1989] dubium] NOTE: This genus is not an ornithomimid as usually classified (R. E. Molnar, pers. Family: ITEMIRIDAE Kurzanov, 1976 comm.), but is probably an allosaurid (Kur- zanov, 1989). Census: 1 genus, 1 species

Genus: Saurophagus Stovall vide Ray, Genus: Itemirus Kurzanov, 1976 1941/Swainson 1831 /. medullaris Kurzanov, 1976 (Type) S. maximus Stovall vide Ray, 1941 (Type) NOTE: This genus is referred to the Carno- NOTE: As shown in Hunt & Lucas, 1987, sauria by Kurzanov (1989). It is probably in­ the description of this large theropod in Ray, determinate (P. J. Currie, pers. comm.). 1941 conforms to proper nomenclatural prac­ tice, and the genus and species are validly des­

Parairrfraclass Archosauria Cope, 1869 113 Theropodomorpha nov. ?D. medius (Marsh, 1888) [nomen dubium] Family: DRYPTOSAURIDAE Marsh, 1890 = Allosaurus medius Marsh, 1888 [nomen dubium] Census: 4 genera (2 doubtful), = Antrodemus medius (Marsh, 1888) 7 species (5 doubtful) [nomen dubium] Genus: Altispinax von Huene, 1923 ?D. potens (Lull, 1911) [nomen dubium] = Altipinax von Huene, 1932 [sic] = Creosaurus potens Lull, 1911 [nomen = Altispanax Stovall & Langston, 1950 [sic] dubium] A. dunkeri (Dames, 1884) (Type) = Megaiosaums dunkeri Dames, 1884 NOTE: The type specimen of the above spe­ Parafamily: AUBLYSODONTIDAE cies is a tooth from the Lower Wealden of Nopcsa, 1928 Hanover presently in the University of Mar­ burg collection (it may be lost: S. Pickering, Census: 3 genera, 4 species pers. comm.)- It resembles teeth referred to = Aublysodontinae Nopcsa, 1928 the genus Dryptosaurus in having no denticles = Shanshanosauridae Dong, 1977 on the mesial carina (Denton, 1990, and pers. comm.), so Altispinax is provisionally referred Genus: Gilmore, 1933 to the family Dryptosauridae; see also Beckle- A. olseni Gilmore, 1933 (Type) spinax and Valdoraptor. = (Alectrosaurus) olseni (Gilmore, 1933) Genus: Diplotomodon Leidy, 1868 [nomen NOTE: The large forelimb referred to this dubium; = Dryptosaurus?] genus probably belongs to a segnosaurid (Per- = Tomodon Leidy, 1865/Dumeril 1853 le, 1977; Mader & Bradley, 1989). A new Alec­ D. horrificus (Leidy, 1865) (Type) trosaurus specimen recently recovered from = Tomodon horrificus Leidy, 1865 [nomen Mongolia (P. Currie, pers. comm.; D. Mclnnes, dubium] pers. comm.) shows close affinity to the "Jor­ NOTE: Originally described as mosasauri- dan theropod" ( molnari) but not an, the tooth that constitutes the type specimen to the Tyrannosauridae, the family in which of the above species was provisionally referred Alectrosaurus had previously been classified. to the Megalosauridae by Welles, 1952, but it most closely resembles the teeth of Dryptosau­ Genus: Aublysodon Leidy, 1868 rus aquilunguis (R. E. Molnar, pers. comm.). = Deinodon Leidy, 1856 (in part) A. mirandus Leidy, 1868 (Type) Genus: Dryptosauroides von Huene, 1932 = Deinodon horridus Leidy, 1856 (in part) [nomen dubium] A. amplus Marsh, 1892 D. grandis von Huene, 1932 (Type) = Deinodon amplus (Marsh, 1892) Genus: Dryptosaurus Marsh, 1877 = Manospondylus amplus (Marsh, 1892) = Dryptosausus von Huene, 1922 [sic] = Tyrannosaurus amplus (Marsh, 1892) = Laelaps Cope, 1866/Koch, 1839 = Aublysodon cristatus Marsh, 1892 D. aquilunguis (Cope, 1866) (Type) [nomen dubium] = Laelaps aquilunguis Cope, 1866 = Deinodon cristatus (Marsh, 1892) ?D. trihedrodon (Cope, 1877) [nomen [nomen dubium] dubium] - Aublysodon molnari Paul, 1988 = Laelaps trihedrodon Cope, 1877 [nomen = Aublysodon molnaris PauL 1988* dubium] NOTE: Aublysodon molnari was originally = Antrodemus trihedrodon (Cope, 1877) described as the "Jordan theropod" (Molnar, [nomen dubium] 1978). It is more fully described in Molnar & NOTE: The above species may be referable Carpenter, 1989, who tentatively refer it to Lei- to Allosaurus (R. E. Molnar, pers. comm.). d/s species Aublysodon mirandus. Because its

Theropodomorpha nov. 114 Mesozoic Meanderings #2 provenance is Lance rather than Judith River, = Tyrannosaurus torosus (D. A. Russell, however, it and A. cristatus are instead referred 1970) to the Lance species Aubfysodon amplus here. = Tyrannosaurus () torosus (D. A. Russell, 1970) Genus: Shanshanosaurus Dong, 1977 [New species to be described by R. T. Bak- S. hucyanshanensis Dong, 1977 ker: the "stretch-snout" Daspletosaurus] = Aubfysodon hucyanshanensis (Dong, 1977) Paul 1988 Genus: Deinodon Leidy, 1856 [nomen dubium] = Shanshanosaurus houyanshanensis — Dinodon Cope, 1866/Dumeril & Bibron, Dong, 1987 [sic] 1853 [sic] D. horridus Leidy, 1856 (Type) Genus: [To be described from Dinosaur Provin­ = Dinodon horridus (Leidy, 1856) [nomen cial Park; D. Mclnnes, pers. comm.] dubium] = horridus (Leidy, 1856) [nomen dubium] Family: TYRANNOSAURIDAE = Megalosaurus horridus (Leidy, 1856) Osborn, 1905 [nomen dubium] = Dryptosaurus kenabekides Hay, 1899 Census: 10 genera (2 doubtful), [nomen dubium] 16 species (4 doubtful) ?D. grandis (Marsh, 1890) [nomen dubium] = Deinodontidae Brown, 1914 " Omithomimus grandis Marsh, 1890 = Deinodontinae Matthew & Brown, 1922 [nomen dubium] = Oinodontidae Cope, 1866 = Aubfysodon grandis (Marsh, 1890) [nomen oblitum] [nomen dubium] - Tyrannosaurinae Matthew & NOTE: The above species probably repre­ Brown, 1922 sents a distinct but presently undefinable tyran- nosaurid genus (Molnar, Kurzanov & Dong, Genus: Albertosaurus Osborn, 1905 1990). = Albeltosaurus Molnar & Carpenter, 1989 [sic] Genus: Gorgosaurus Lambe, 1914 ( = Alberto­ A. sarcophagus Osborn, 1905 (Type) saurus'!) = Albertosaurus arctunguis Parks, 1928 = Zatomis Stephenson, 1912 [sic, for = Deinodon arctunguis (Parks, 1928) Zatomus; specimen referred to ?Gor- gosaurus by Miller, 1967] A. megagracilis Paul, 1988 G. libratus Lambe, 1914 (Type) Genus: Kurzanov, 1976 = Albertosaurus libratus (Lambe, 1914) A. remotus Kurzanov, 1976 (Type) = Deinodon libratus (Lambe, 1914) = Laelaps incrassatus Cope, 1876 [nomen Genus: Chingkankousaurus Young, 1958 ( = dubium] ?) = Chingkankonsaurus Romer, 1966 [sic] = Deinodon incrassatus (Cope, 1876) = Chingkankouensis Young, 1958 [sic] [nomen dubium] = Chingkankousarurus Young, 1958 [sic] - Dryptosaurus incrassatus (Cope, 1876) = Chingkonkousaurus Dong, 1973 [sic] [nomen dubium] = Chinkankousaurus Rozhdestvensky, 1977 - Laelaps falculus Cope, 1876 [nomen [sic] dubium] Cfragiiis Young, 1958 (Type) = Deinodon falculus (Cope, 1876) [nomen = Chingkankouensis fragilis Young, 1958 dubium] [sic] = falculus (Cope, 1876) [nomen dubium] Genus: Daspletosaurus D. A. Russell, 1970 = Dryptosaurus falculus (Cope, 1876) D. torosus D. A. Russell, 1970 (Type) [nomen dubium]

Parainfraclas s Archosauria Cope, 1869 115 Theropodomorpha nov. = Laelaps hazenianus Cope, 1876 [nomen = Tyrannosaurus (Tyrannosaurus) bataar dubium] (Maleev, 1955) — Deinodon hazenianus (Cope, 1876) = Albertosaurus periculosus Riabinin, 1930 [nomen dubium] [nomen dubium] = Dryptosaurus hazenianus (Cope, 1876) = Alectosaurus periculosus (Riabinin, [nomen dubium] 1930) [nomen dubium] G. Sternberg Matthew & Brown, 1923 = Deinodon periculosus (Riabinin, 1930) = Gorgosaurus Sternberg Matthew & [nomen dubium] Brown, 1922 [nomen nudum] - Gorgosaurus lancinator Maleev, 1955 = Albertosaurus Sternberg (Matthew & (juvenile) Brown, 1923) = Aublysodon lancinator (Maleev, 1955) = Deinodon Sternberg (Matthew & (juvenile) Brown, 1923) = Tarbosaurus efremovi Maleev, 1955 NOTE: The above species may be a juvenile ?T. turpanensis (Zhai, Zheng & Tong, 1978) Gorgosaurus libratus (D. A. Russell, 1970), but n. comb, [nomen nudum] it may also represent a different tyrannosaurid = Tyrannosaurus turpanensis Zhai, Zheng genus altogether (G. Paul, pers. comm.). & Tong, 1978 [nomen nudum] TV. luonchuonensis (Dong, 1979) n. comb. Genus: Nanotyrannus Bakker, Williams & Cur­ = Tyrannosaurus luonchuonensis Dong, rie, 1988 1979 = Clevelanotyrannus Bakker, Williams & ?T. lanpingensis (Zhao, 1986) n. comb. Currie vide Currie, 1987 [nomen nudum] [nomen nudum] iV. lancensis (Gilmore, 1946) (Type) = Tyrannosaurus lanpingi Zhao, 1986 [no­ = Gorgosaurus lancensis Gilmore, 1946 men nudum] = Albertosaurus lancensis (Gilmore, 1946) = Tyrannosaurus lanpingensis Yeh, 1975 = Albertosaurus (Nanotyrannus) lancensis [nomen nudum] (Gilmore, 1946) NOTE: T. lanpingensis may be from the = Deinodon lancensis (Gilmore, 1946) Upper Jurassic of China and thus not referable NOTE: The generic name Clevelanotyran­ to either Tarbosaurus or Tyrannosaurus (Yeh, nus Bakker, WtUiams & Currie was published 1975; R. E. Molnar, pers. comm.). in the bibliography of Currie, 1987, in Fourth Large teeth and other fragmentary tyranno­ Symp. Mesozoic Terrestrial Ecosystems, Short saurid specimens from the Upper Cretaceous Papers, pp. 52-60. It was changed before the of Asia are best referred to the Asian genus genus was formally described. Tarbosaurus instead of the North American Genus: Prodeinodon Osborn, 1924 [nomen genus Tyrannosaurus until the presence of Ty­ dubium; = Alectrosaurusl] rannosaurus can be unequivocally documented = Prodeidon Hou, Yeh & Zhao, 1975 [sic] in Asia. = Prodinodon Hu, 1964 [sic] P. mongoliensis Osborn, 1924 (Type) Genus: Tyrannosaurus Osborn, 1905 = Prodeinodon mongoliense Osborn, 1924* = Dynamosaurus Osborn, 1905 = Deinodon mongoliensis Bohlin, 1953 [sic] = Manospondylus Cope, 1892 [nomen P. kwangshiensis Hou, Yeh & Zhao, 1975 oblitum] [nomen dubium] = Monospondylus Maleev, 1968 [sic] = Tiranosaurus Kurzanov & Tumanova, Genus: Tarbosaurus Maleev, 1955 1978 [sic] = Alectosaurus Young, 1958 [sic, for = Tryannosaurus Parks, 1928 [sic] Alectrosaurus] = Tyannosaurus Hu & Cheng, 1988 [sic] = Tarbosaurus Maleev, 1955 [sic] = Tyrannosaurs Stokes, 1988 [sic] T. bataar (Maleev, 1955) (Type) = Tyrannus Ulanov, 1978/Lacepede, 1799 = Tyrannosaurus bataar Maleev, 1955 [sic]

Theropodomorpha nov. 116 Mesozoic Meanderings #2 = Tyranosaums Guggisberg, 1966 [sic] Genus: [To be described by Bakker & Currie; T. rex Osborn, 1905 (Type) based on the tyrannosaurid skeleton on dis­ = Tyrannosaums (Tyrannosaums) rex (Os­ play at the Field Museum in Chicago, present­ born, 1905) ly labeled Albertosaurus libratus] = Manospondylus gigas Cope, 1892 Genus: [To be described from the Horseshoe [nomen oblitum] Canyon Formation of Alberta; may simply be = Dynamosaums imperiosus Osborn, 1905 a new species of Albertosaurus; Bakker, Wil­ NOTE: R. T. Bakker (pers. comm.) believes liams & Currie 1988] material referred to Tyrannosaums rex belongs in two distinct species. These may, however, simply be sexual dimorphs (K. Carpenter, pers. comm.). CARNOSAURIA incertae sedis [New species to be described; originally noted in D. Lawson's doctoral dissertation; Census: 2 doubtful genera, based on a dentary from a large theropod 2 doubtful species that may not be tyrannosaurid; Carpenter, Genus: Rapator von Huene, 1932 [nomen 1990] dubium] Genus: (To be described by Carpenter (in R. omitholestoides von Huene, 1932 (Type) press)] NOTE: This genus may be an abelisaurid [Type species to be redescribed] (R. E. Molnar, pers. comm.). = Gorgosaurus novojilovi Maleev, 1955 Genus: Walgettosuchus von Huene, 1932 = Albertosaurus novojilovi (Maleev, 1955) [nomen dubium] = Aubfysodon novojilovi (Maleev, 1955) W. woodwardi von Huene, 1932 (Type) = Deinodon novojilovi (Maleev, 1955) = Megalosaums woodwardi (von Huene, 1932) [nomen dubium]

Parainfraclass Archosauria Cope, 1869 117 Theropodomorpha nov. Notes and New Taxa

Theropodomorpha nov. 118 Mesozoic Meanderings #2 Parasuperorden Theropodomorpha nov. (continued)

Paraorden Theropoda Marsh, 1881 (continued) Parasuborden Protoaviformes Chatterjee, 1991 Census: 1 family, 1 genus, 1 species = Protoavis Chatterjee, 1986 [nomen Family: PROTOAVIDAE Chatterjee, 1991 nudum] P. texensis Chatterjee, 1991 (Type) Census: 1 genus, 1 species Genus: Protoavis Chatterjee, 1991 Suborder Coelurosauria von Huene, 1914 Census: 3 families, 20 genera (10 doubtful), 21 species (10 doubtful)

Family: COMPSOGNATHIDAE Family: COELURIDAE Marsh, 1881 Cope, 1875 Census: 18 genera (10 doubtful), Census: 1 genus, 2 species 18 species (10 doubtful) = Compsognathinae Nopcsa, 1923 = Coelurosauridae Cope, 1882 = Ornitholestinae Paul, 1988 Genus: Compsognathus Wagner, 1859 NOTE: This family, named after a genus of = Campsognothus Stokes, 1988 [sic] uncertain relationships, has become a "grab- C. longipes Wagner, 1859 (Type) bag" for small theropod genera based on frag­ C. corallestris Bidar, Demay & Thomel, 1972 mentary remains. Further study of the genera = Compsognathus corralestris Callison & included herein may disclose that many can be Quimby, 1984 [sic] classified in other theropod families. NOTE: Ostrom (1978) and Norman (1990) regard the two species of Compsognathus as sy­ Genus: Seeley, 1887 [nomen nonymous, but European workers (Fabre, de dubiwn] Broin, Ginsburg & Wenz, 1982; Taquet, 1985) = Fox, 1866 [nomen maintain their distinctness. nudum] A. pusillus (Owen, 1876) (Type) Genus: [To be described from the Toarcian = Poikiiopleuron pusillus Owen, 1876 (upper Lower Jurassic) of Morocco; Jenny, [nomen aubium] Jenny-Deshusses, la Marrec & Taquet, 1980; Taquet, 1985] = Calamospondylus oweni Fox, 1866 [nomen nudum]

Parainfraclass Archosauria Cope, 1869 119 Theropodomorpha nov. = Poecilopleuron minor Owen vide Cope, Genus: Nuthetes Owen, 1854 1878 [sic] = Nothetes Morris, 1854 [sic] NOTE: The above genus may be a compso- N. destructor Owen, 1854 (Type) gnathid (R. E. Molnar, pers. comm.). = Megalosaurus destructor (Owen, 1854) = Nuthetes destrictor Kuhn, 1965 [sic] Genus: Calamospondylus Lydekker, 1889 NOTE: The type specimen of the above spe­ [nomen dubium; = Aristosuchusl] cies has been described as lacertilian, but it is = Calamosaums Lydekker, 1891 [nomen probably a small theropod. The "granicones" dubium] associated with the specimen are likely armor C. fad Lydekker, 1889 (Type) scutes of a basal ankylosaurian (Gallon, 1986). = Calamosaums faxi (Lydekker, 1889) Nuthetes is referred to this family provisionally. [nomen dubium] Genus: Omitholestes Osborn, 1903 Genus: Chuandongocoelurus He, 1984 = Orintholestes Breed, 1968 [sic] C. primitivus He, 1984 (Type) O. hermanni Osborn, 1903 (Type) Genus: Coeluroides von Huene, 1932 [nomen = Coelurus hermanni (Osborn, 1903) dubium] NOTE: This genus is regarded as a small al- C. largus von Huene, 1932 (Type) losaurid by Paul, 1988. Genus: Coelurus Marsh, 1879 Genus: Proceratosaurus von Huene, 1926 Cfragilis Marsh, 1879 (Type) P. bradleyi (Woodward, 1910) (Type) = Coelurus agilis Marsh, 1884 = Megalosaurus bradleyi Woodward, 1910 = Elaphrosaums agilis (Marsh, 1884) NOTE: Paul, 1988 refers the above genus to the subfamily Ornitholestinae of the family Al- Genus: Inosaurus de Lapparent, 1960 [nomen losauridae. dubium] I. tedreftensis de Lapparent, 1960 (Type) Genus: Sinocoelurus Young, 1942 [nomen dubium] Genus: Jubbulpuria von Huene, 1932 [nomen = Sinosaurus Dong, 1979/Young, 1948 [sic] dubium] S. fragilis Young, 1942 (Type) J. tenuis von Huene, 1932 (Type) Genus: Madsen, 1974 Genus: Kakuru Molnar & Pledge, 1980 S. clevelandi Madsen, 1974 (Type) K. kujani Molnar & Pledge, 1980 (Type) = Iliosuchus clevelandi (Madsen, 1974) NOTE: The above genus is included in this NOTE: The above genus is included in this family provisionally. family provisionally (Madsen, 1976; Dodson, Genus: von Huene, 1932 [nomen Behrensmeyer & Bakker, 1980). It may be an dubium] allosaurid (R. E. Molnar, pers. comm.). L. indicus von Huene, 1932 (Type) Genus: Teinurosaurus Nopcsa, 1928 emend. NOTE: The above genus has cervical ver­ 1929 [nomen dubium] tebrae similar to those of and con­ = Caudocoelus von Huene, 1932 [nomen sequently may be an oviraptorosaur (R. E. Mol­ dubium] nar, pers. comm.). T. sauvagei (von Huene, 1932) Olshevsky, Genus: Madsen, 1976 1978 (Type) M. bicentesimus Madsen, 1976 (Type) = Caudocoelus sauvagei von Huene, 1932 NOTE: The above genus is included in this [nomen dubium] family provisionally (Madsen, 1976; Dodson, = Iguanodon prestwichii Sauvage, 1897/8 Behrensmeyer & Bakker, 1980). It may be a eu- non Hulke, 1880 streptospondylid (PauL 1988). Genus: Ngedsaurus Zhao, 1983 [nomen nudum] N. dapukaensis Zhao, 1986 (Type)

Theropodomorpha nov. 120 Mesozoic Meanderings #2 Genus: Thecocoelums von Huene, 1923 [nomen Genus: [To be described from the Fruita For­ dubium; = Aristosuchusl] mation of Colorado; Rasmussen & Callison, = Therocoelurus von Huene, 1956 [sic] 1981] T. daviesi (Seeley, 1888) (Type) = Thecospondylus daviesi Seeley, 1888 [nomen dubium] Family: AVISAURIDAE = Coelums daviesi (Seeley, 1888) [nomen Brett-Surman & Paul, 1985 dubium] Genus: Tugulusaurus Dong, 1973 [nomen Census: 1 genus, 1 species dubium] Genus: Avisaums Brett-Surman & Paul, 1985 = Tugulosaurus Dong, 1980 [sic] A. archibaldi Brett-Surman & Paul, 1985 T.faciles Dong, 1973 (Type) (Type) NOTE: This genus may be an enantiornithid bird (Bonaparte, 1986). It is included here pro­ visionally. Suborder Omithomimosauria Barsbold, 1976 Census: 2 families, 11 genera (1 doubtful), 20 species (5 doubtful) to be a species of Archaeomithomimus; D. Family: ORNITHOMIMIDAE Marsh, 1890 Chure, pers. coram.] = Arkanosaurus Sattler, 1983 [sic] Census: 10 genera (1 doubtful), "A. fridayi" [to be described] 19 species (5 doubtful) Genus: Betasuchus von Huene, 1932 [nomen = Garudimimidae Barsbold, 1981 dubium] = Garudimiminae Paul, 1988 = Omithomimidorum gen. b von Huene, = Harpymimidae Barsbold & Perle, 1984 1926 [nomen oblitum] = Ornithomiminae Nopcsa, 1923 B. bredai (Seeley, 1883) (Type) Genus: Barsbold, 1988 = Megalosaurus bredai Seeley, 1883 A. planinychus Barsbold, 1988 (Type) [nomen dubium] = Omithomimidorum gen. b bredai Genus: Archaeomithomimus D. A. Russell, 1972 (Seeley, 1883) [nomen oblitum] = Archeomithomimus Kranz, 1989 [sic] ?A. affinis (Gilmore, 1920) Genus: Dromiceiomimus D. A. Russell, 1972 = Coelosaurus affinis Gilmore, 1920 D. brevetertius (Parks, 1926) (Type) = Omithomimus affinis (Gilmore, 1920) = brevetertius Parks, 1926 = Omithomimus (Archaeomithomimus) af­ = Omithomimus brevetertius (Parks, 1926) finis (Gilmore, 1920) = Dromiceiomimus brevitertius D. A. Rus­ = AUosaurus medius Marsh, 1888 (in part) sell, 1972 [sic] = grandis Lull, 1911 [nomen - Struthiomimus ingens Parks, 1933 dubium] = Omithomimus ingens (Parks, 1933) A. asiaticus (Gilmore, 1933) (Type) D. samueli (Parks, 1928) = Omithomimus asiaticus Gilmore, 1933 = Struthiomimus samueli Parks, 1928 = Omithomimus (Archaeomithomimus) = Omithomimus samueli (Parks, 1928) asiaticus (Gilmore, 1933) Genus: Janensch, 1920 = Omithomimus asistiecus Dong, 1979 [sic] = Elephrosaurus Paul, 1988 [sic] Genus: "Arkansaurus" [to be described; a prim­ E. bambergi Janensch, 1920 (Type) itive ornithomimid from Arkansas; may prove

Parairrfraclass Archosauria Cope, 1869 121 Theropodomorpha nov. ?E. iguidiensis de Lapparent, 1960 [nomen NOTE: The above species may not be an or- dubium] nithomimid (R. E. Molnar, pers. comm.). ?E. gautieri de Lapparent, 1960 [nomen O. velox Marsh, 1890 (Type) dubium] ?0. tenuis Marsh, 1890 [nomen dubium] NOTE: The above genus is referred to the O. sedens Marsh, 1892 Podokesauridae (as the Coeiophysidae) by O. edmontonensis C. M. Sternberg, 1933 Paul (1988). = Omithomimus edmontonicus C. M. Sternberg, 1933* Genus: Galtimimus Osm61ska, Roniewicz & = Struthiomimus currelli Parks, 1933 Barsbold, 1972 = Omithomimus edmontonianus Kuhn, = Callimimus Barsbold, 1983 [sic] 1965 [sic] G. bullatus Osm61ska, Roniewicz & [New species to be described; Leahy, 1987] Barsbold, 1972 (Type) = Omithomimus bullatus (Osmdlska, Genus: "Sanchusaurus" Hisa, 1988 [in Utan Roniewicz & Barsbold, 1972) Scientific Magazine #4: 24; based on a frag­ mentary caudal vertebra from Japan; possibly Genus: Gamdimimus Barsbold, 1981 the oldest and largest-known omithomimid G. brevipes Barsbold, 1981 (Type) (Manabe & Hasegawa, 1991)] Genus: Barsbold & Perle, 1984 Genus: Struthiomimus Osborn, 1916 = Harpimimus Currie, 1989 [sic] S. alius (Lambe, 1902) (Type) H. okladnikovi Barsbold & Perle, 1984 = Omithomimus altus Lambe, 1902 (Type) Genus: [To be described from Argentina; with Genus: Omithomimus Marsh, 1890 unfused metatarsals; J. F. Bonaparte, pers. = Coelosaurus Leidy, 1865/[Anonymous, comm.; J. S. Mcintosh, pers. comm.] but known to be Owen] 1854 = Coelurosaums White, 1973 [sic] Genus: [To be described from Argentina; with = Omithomimidomm gen. a von Huene, fused metatarsals and a metatarsal III that is 1926 [nomen oblitum] almost pinched out of existence; J. F. Bona­ = Omithominus Nopcsa, 1918 [sic] parte, pers. comm.; J. S. Mcintosh, pers. ?0. antiquus (Leidy, 1865) comm.] = Coelosaurus antiquus Leidy, 1865 = Struthiomimus antiquus (Leidy, 1865) Genus: [To be described from the Dockum = Laelaps macropus Cope, 1868 [nomen Formation of Texas; based on a nearly com­ dubium] plete skull; Chatterjee, 1991 SVP annual meet­ ing abstracts] = Dryptosaurus macropus (Cope, 1868) [nomen dubium] NOTE: Recent work by T. R. Holtz, Jr. Family: DEINOCHEIRIDAE (doctoral dissertation) indicates that Coelosau­ rus is probably not an omithomimid (reported Osmdlska & Roniewicz, 1970 inBW#152). ?0. lonzeensis (Dollo, 1883) [nomen dubium] Census: 1 genus, 1 species = Megalosaurus lonzeensis Dollo, 1883 = Deinocheirinae Paul, 1988 [nomen dubium] - Omithomimidomm gen. a lonzeensis Genus: Osmolska & Roniewicz, (Dollo, 1883) [nomen oblitum] 1970 D. mirificus Osmdlska & Roniewicz, 1970 (Type)

Theropodomorpha nov. 122 Mesozoic Meanderings #2 Suborder: Deinonychosauria Colbert & D. A. Russell, 1969 Census: 3 families, 18 genera (5 doubtful), 29 species (14 doubtful) Genus: Palaeopteryx Jensen, 1981 [nomen Parafamily: ARCHAEOPTERYGIDAE dubium] Huxley, 1871 P. thomsoni Jensen, 1981 (Type) NOTE: Originally described as a primitive Census: 3 genera (1 doubtful), avian, the above genus may represent a small 4 species (2 doubtful) deinonychosaur, probably an archaeopterygjd— although the type specimen is indeterminate Genus: Archaeopteryx von Meyer, 1861 (Jensen & Padian, 1989). = Archaeopterix [Anonymous] 1861 [sic] = Archaeomis Petronievics vide Petronie- vics & Woodward, 1917 = Archeopteryx Owen, 1864 [sic] Family: DROMAEOSAURIDAE = Griphomis Woodward, 1962 [sic] D. A. Russell, 1969 = Griphosaurus Wagner, 1861 = Gryphomis Lambrecht, 1933 [sic] Census: 10 genera (3 doubtful), = Gryphosaums MarschalL 1873 [sic] 17 species (10 doubtful) A. Uthographica von Meyer, 1861 (Type) = Pterodactylus crassipes von Meyer, 1857 = Bradycnemidae Harrison & [nomen oblitum] C. A. Walker, 1975 = Dromaeosaurinae Matthew & = Archaeopteryx crassipes (von Meyer, Brown, 1922 1857) [nomen oblitum] = Barsbold, 1978 = Rhamphorhynchus crassipes (von Meyer, 1857) [nomen oblitum] Genus: Barsbold, 1983 = Scaphognathus crassipes (von Meyer, = Adasaurus Barsbold, 1978 [nomen nudum] 1857) [nomen oblitum] A. mongoliensis Barsbold, 1983 (Type) = Griphosaurus problematicus Wagner, 1861 Genus: Bradycneme Harrison & C. A. Walker, 1975 [nomen dubium] = Archaeopteryx macrura Owen, 1862 B. draculae Harrison & C. A. Walker, 1975 = Griphosaurus longicaudatus Owen, 1862 (Type) = Griphosaurus longicaudatum Owen, NOTE: Described as a genus of large , 1862 [sic] the above "almost certainly represents a thero- = Gryphomis longicaudatus (Owen, 1862) pod dinosaur" (Brodkorb, 1978). Based on the = Archaeopteryx macrurus Owen, 1863 [sic] structure of the astragalus, it is a dromaeosau- = Archaeopteryx macroura Vogt, 1879 [sic] rid (R. E. Molnar, pers. comm.). = Archaeopteryx siemensii Dames, 1897 = Archaeomis siemensii (Dames, 1897) Genus: Ostrom, 1969 = Archaeopteryx oweni Petronievics, 1917 = Daptosaurus Brown, 1933 vide Chure & ?A. vicensensis [Anonymous] vide Lam­ Mcintosh, 1989 brecht, 1933 [nomen dubium] = Deynonychus Bonaparte, 1978 [sic] NOTE: The above species is a pterosaur, ac­ = Dienynochus Dong, 1980 [sic] cording to O. Heinschmidt (Brodkorb, 1978). - Koreanosaurus Kim, 1979 [nomen nudum] = Koreasaurus Kim, 1979 [sic] Genus: Jurapteryx Howgate, 1985 D. antirrhopus Ostrom, 1969 (Type) /. recurva (Howgate, 1984) (Type) = antirrhopus (Ostrom, 1969) = Archaeopteryx recurva Howgate, 1984 = Daptosaurus agilis Brown, 1933 vide NOTE: Most workers regard this species as Chure & Mcintosh, 1989 a synonym of Archaeopteryx Uthographica.

Parainfraclass Archosauria Cope, 1869 123 Theropodomorpha nov. NOTE: Koreanosaums, based on a femur, Genus: "Kitadanisaurus" Lambert, 1990 [an in­ was initially described as a deinodontid (tyran- determinate dromaeosaurid from Japan; Ma- nosaurid), but Kim (1983) referred to the fe­ nabe & Hasegawa, 1991] mur as possibly hypsilophodontid, and recently (pers. comm., 1986) he states it may be refera­ Genus: Cope, 1876 [nomen ble to Deinonychus. Lacking a type species, the aubium] genus Koreanosaums is a nomen nudum. Paul = Triprotodon Chure & Mcintosh, 1989 [sic] (1988) synonymizes Deinonychus with Veloci- = Zapsalis Cope, 1876 [nomen aubium] raptor, but Ostrom (1990) rejects this as unwar­ P. lacustris Cope, 1876 (Type) ranted. = Zapsalis abradens Cope, 1876 [nomen aubium] Genus: Dromaeosaums Matthew & Brown, P. caperatus (Marsh, 1889) [nomen aubium] 1922 = Tripriodon caperatus Marsh, 1889 ?D. cristatus (Cope, 1876) [nomen dubium] [nomen aubium] = Laelaps cristatus Cope, 1876 [nomen = caperatus (Marsh, 1889) aubium] [nomen aubium] - Dryptosaums cristatus Cope, 1876 = Triprotodon caperatus ((Marsh, 1889) [nomen aubium] Chure & Mcintosh, 1989 [sic] ?D. explanatus (Cope, 1876) [nomen aubium] Genus: Phaedrolosaums Dong, 1973 [nomen = Laelaps explanatus Cope, 1876 [nomen aubium] aubium] P. ilikensis Dong, 1973 (Type) - Deinodon explanatus (Cope, 1876) [nomen aubium] Genus: Sauromitholestes Sues, 1978 ~ Dryptosaums explanatus (Cope, 1876) 5. langstoni Sues, 1978 (Type) [nomen aubium] = Velociraptor langstoni (Sues, 1978) Paul, ?D. laevifrons (Cope, 1876) [nomen aubium] 1988 = Laelaps laevifrons Cope, 1876 [nomen Genus: Velociraptor Osborn, 1924 aubium] = Ovoraptor Osborn, 1924 [nomen nudum] = Dryptosaums laevifrons (Cope, 1876) = Velociraptoe Dong, 1977 [sic] [nomen aubium] V. mongoliensis Osborn, 1924 (Type) ?D. lateralis (Cope, 1876) [nomen aubium] = Ovoraptor djadochtari Osborn, 1924 = Aublysodon lateralis Cope, 1876 [nomen aubium] [nomen nudum] = Deinodon lateralis (Cope, 1876) [nomen Genus: [To be described from the Lower Cre­ aubium] taceous of Utah; ?D. gracilis (Marsh, 1888) [nomen aubium] noted by Chure in the June 1984 SVP Bulletin] =* Coelums gracilis Marsh, 1888 [nomen aubium] Genus: [To be described from the Late Cre­ ?D. minutus (Marsh, 1892) [nomen aubium] taceous of Mongolia; a large dromaeosaurid = Omithomimus minutus Marsh, 1892 about 4 meters long; P. Currie, pers. comm.; [nomen aubium] D. Mclnnes, pers. comm.] D. albertensis Matthew & Brown, 1922 Genus: [To be described from the Late Creta­ (Type) ceous of Provence, France; material includes teeth and postcrania, and more than one tax- Genus: Euronychodon Telles Antunes & Sigog- on may be present; Buffetaut, Cuny & Le neau-Russell, 1991 Loeuff, 1991] E. portucalensis Telles Antunes & Sigog- neau-RusselL 1991 (Type) Genus: Hulsanpes Osmblska, 1982 H. perlei Osmolska, 1982 (Type)

Theropodomorpha nov. 1 Mesozoic Meanderings #2 cies is best placed provisionally in the genus Family: TROODONTIDAE Gilmore, 1924 Sauromithoides. Census: 5 genera (1 doubtful), Genus: "" [Anonymous] 1990 [to 8 species (3 doubtful) be described by D. A. Russell & Dong Z. from a Lower Cretaceous formation in the Or- = Saurornithoididae Barsbold, 1974 dos Basin of Inner Mongolia; name published = Troddorrtidae Gilmore, 1924* in Update, an Ex Terra Foundation publica­ Genus: Osmdlska, 1987 tion] B. gracilicrus Osm61ska, 1987 (Type) Genus: Tochisaunis Kurzanov & Osmolska, Genus: Heptasteomis Harrison & C. A. 1991 Walker, 1975 [nomen dubium) T. nemegtensis Kurzanov & Osm61ska, 1991 H. andrewsi Harrison & C. A. Walker, 1975 (Type) (Type) Genus: Troodon Leidy, 1856 = Troodon andrewsi (Harrison & C. A. = Troodon Leidy, 1856* Walker, 1975) [nomen dubium] = Pectinodon Carpenter, 1982 NOTE: Described as a genus of large owls, = Pofydontosaurus Glut, 1972 [sic] the above "almost certainly represents a thero- = Polyodontosaums Sternberg, 1932 pod dinosaur" (Brodkorb, 1978). Based on die = Sternberg, 1932 structure of the astragalus, it is a troodontid T. formosus Leidy, 1856 (Type) (Paui, 1988). = Troodon formosus Leidy, 1856* Genus: Sauromithoides Osborn, 1924 (= Troo­ = formosum (Leidy, 1856) don!) = Stegoceras formosus (Leidy, 1856)* = Omithoides Osborn, 1924 [nomen nudum] =» Stenonychosaurus inetjualis Sternberg, = Sauronithoides Maryanska, 1977 [sic] 1932 S. mongoliensis Osborn, 1924 (Type) = Sauromithoides inequalis (Sternberg, = Troodon mongoliensis (Osborn, 1924) 1932) = Omithoides oshiensis Osborn, 1924 = Polyodontosaums grandis Sternberg, [nomen nudum] 1932 S. junior Barsbold, 1974 T. bakkeri (Carpenter, 1982) n. comb. ?S. asiamericanus (Nessov, 1985) n. comb. [nomen dubium] [nomen dubium] - Pectinodon bakkeri Carpenter, 1982 — Pectinodon asiamericanus Nessov, 1985 [nomen dubium] [nomen dubium] NOTE: The above species is provisionally re­ NOTE: Synonymy of Pectinodon with Troo­ tained for Lance Troodon teeth. don (Curie, 1987) indicates that the above spe­ Suborden Oviraptorosauria Barsbold, 1976 Census: 4 families, 7 genera, 10 species [sic] Family: CAENAGNATHIDAE = Caenognathus Langston, 1965 [sic] R. M. Sternberg, 1940 = Chaenagnathus Gregory, 1951 [sic] = Coenagnathus Gradzinski, Kielan- Census: 1 genus, 2 species Jaworowska & Maryanska, 1977 [sic] = Caenagnathinae Paul, 1988 C. collinsi R. M. Sternberg, 1940 (Type) C. stembergi Cracraft, 1971 Genus: R. M. Sternberg, 1940 = Caegnathus Molnar & Carpenter, 1989

Parainfraclass Archosauria Cope, 1869 125 Theropodomorpha nov. Family: ELMISAURIDAE Family: OVIRAPTORIDAE Osmblska, 1981 Barsbold, 1976

Census: 3 genera, 4 species Census: 2 genera, 3 species Genus: Chimstenotes Gilmore, 1924 = Oviraptorinae Barsbold, 1981 = Cheirostenotes Nopcsa, 1928 [sic] Genus: Conchoraptor Barsbold, 1986 = Macrophalangia C. M. Sternberg, 1932 C. pergracilis Gilmore, 1924 (Type) C. gracilis Barsbold, 1986 (Type) = Macrophalangia canadensis C. M. Genus: Oviraptor Osborn, 1924 Sternberg, 1932 = Fenestmsaurus Osborn, 1924 [nomen NOTE: A newly described partial skeleton nudum] effectively establishes the synonymy of the two O. philoceratops Osborn, 1924 (Type) genera Chimstenotes and Macrophalangia (Cur- = Oviraptor (Oviraptor) philoceratops (Os­ rie & D. A. Russell, 1988). born, 1924) = Fenestmsaurus philoceratops Osborn, Genus: Osmdlska, 1981 1924 [nomen nudum] E. rams Osmdlska, 1981 (Type) O. mongoliensis Barsbold, 1986 = Chimstenotes rams (Osm61ska, 1981) E. elegans (Parks, 1933) Genus: [To be described from the Late Creta­ = Omithomimus elegans Parks, 1933 ceous of Mongolia; possesses a didactyl = Chimstenotes elegans (Parks, 1933) manus and may represent a new family; D. = Macrophalangia elegans (Parks, 1933) Mclnnes, pers. coram.] Genus: Micmvenator Ostrom, 1970 = Megadontosaurus Brown, 1933 vide Chure & Mcintosh, 1989 Family: INGENIIDAE Barsbold, 1986 = Micmventer Stokes, 1988 [sic] M. celer Ostrom, 1970 (Type) Census: 1 genus, 1 species = Megadontosaurus ferox Brown, 1933 = Ingeniinae Barsbold, 1981 vide Chure & Mcintosh, 1989 ?M. chagyabi Zhao, 1986 [nomen nudum) Genus: Ingenia Barsbold, 1981 /. yanshini Barsbold, 1981 (Type) = Oviraptor (Ingenia) yanshini (Barsbold, 1981) Suborder: Avimimiformes Chatterjee, 1991 Census: 1 family, 1 genus, 1 species Genus: [To be described from the Late Creta­ Family: AVIMIMIDAE Kurzanov, 1981 ceous Erenhot Formation of Mongolia; may be merely a new species of Avimimus; P. J. Census: 1 genus, 1 species Currie, pers. comm.] Genus: Avimimus Kurzanov, 1981 A. portentosus Kurzanov, 1981 (Type)

Theropodomorpha nov. 126 Mesozoic Meanderings #2 Theropoda incertae sedis Census: 5 genera (3 dot ), 5 species (3 doubtful) Genus: Macrodontophion Zborzewski, 1834 [no- tooth of Orthogoniosaums matleyi in a number men dubium) of features that suggest it is from a different No type species named part of the jaw of the same genus, if not the NOTE: This genus is based on a tooth usual­ same species. ly considered to be megalosaurid. It could well Genus: Patricosaurus Seeley, 1887 [nomen dubi­ belong to a crocodilian or a plesiosaur (R. E. um] Molnar, pers. comm.). P. merocratus Seeley, 1887 (Type) Genus: Omithodesmus Seeley, 1887 NOTE: The above genus, based on the prox­ O. cluniculus Seeley, 1887 (Type) imal end of a femur, is not lacertilian as origi­ NOTE: This genus, usually classified in its nally classified but is probably an indetermi­ own pterosaur family, Ornithodesmidae Hoo- nate small theropod (R. E. Molnar, pers. ley, 1913, was recently determined to be a small comm.). theropod dinosaur by S. Howse & Andrew Mil- Genus: Currie, Rigby & Sloan, ner (SVP Bulletin #145: 43; Wellnhofcr, 1991). 1990 Genus: Orthogoniosaums Das-Gupta, 1931 [no- = Ricardoestesia Currie, Rigby & Sloan, men dubium] 1990 [sic] O. rawest (Lydekker, 1890) n. comb, [nomen R. gilmorei Currie, Rigby & Sloan, 1990 dubium] (Type) = Massospondylus rawest Lydekker, 1890 NOTE: The above genus is based on a small [nomen dubium] dentary originally referred to in = Megalosawus rawesi (Lydekker, 1890) Gilmore, 1924. Vianey-Liaud, Jain & Sahni, 1987 [nomen Genus: [To be described from the Late Creta­ dubium] ceous of Mongolia; represents a new family of O. matleyi Das-Gupta, 1931 (Type) small theropods with a monodactyl manus; P. NOTE: The tooth that is the type specimen J. Currie, pers. comm.] of Massospondylus rawesi resembles the type

Parairrfraclass Archosauria Cope, 1869 127 Theropodomorpha nov. Notes and New Taxa

Theropodomorpha nov. 128 Mesozoic Meanderings #2 Superorden Sauropodomorpha von Huene, 1932

Census: 2 orders, 18 families, 96 genera (19 doubtful), 151 species (41 doubtful)

Order: Brontosauria nov. Census: 2 suborders, 16 families, 91 genera (19 doubtful), 145 species (41 doubtful) Parasuborden Prosauropoda von Huene, 1920 Census: 7 families, 18 genera (3 doubtful), 23 species (6 doubtful) suchid, or theropod) and is not a prosauropod Family: THECODONTOSAURIDAE (Galton, 1985). Lydekker, 1890 TT. minor Haughton, 1918- [nomen dubium] = Thecodontosaurus browni von Huene, Census: 3 genera (2 doubtful), 1932 non Seeley, 1895 [nomen dubium) 5 species (4 doubtful) = Thecodontosaurus minimus Ellenberger, Genus: Agrosaurus Seeley, 1891 [nomen 1970 [sic; probably an error for Thecodon­ dubium] tosaurus minor] A. macgillivrayi Seeley, 1891 (Type) = Thecodontosaurus macgillivrayi (Seeley, 1891) Family: ANCHISAURIDAE Marsh, 1885

Genus: Dutuit, 1972 [nomen Census: 1 genus, 3 species dubium) = Azandohosaurus Gallon, 1978 [sic] = Amphisauridae Marsh, 1882 = Azandohsaurus Dutuit, 1972 [sic] Genus: Anchisaurus Marsh, 1885 A. laaroussii Dutuit, 1972 (Type) = Amphisaurus Marsh, 1877 [nomen nudum] Genus: Thecodontosaurus Riley & Stutchbury, = Amphisaurus Marsh, 1882/Barkas, 1870 1836 = Gyposaurus Broom, 1911 T. antiquus Morris, 1843 (Type) = Megadactylus Hitchcock, 1865/Fitzinger, TT. elizae (Sauvage, 1907) von Huene, 1908 1843 [nomen dubium] = Yaleosaurus von Huene, 1932 = Plateosaurus elizae Sauvage, 1907 A. pofyzelus (Hitchcock, 1865) (Type) [nomen dubium] = Megadactylus pofyzelus Hitchcock, 1865 NOTE: This species is based on the teeth of = Amphisaurus pofyzelus (Hitchcock, 1865) a (rauisuchid, herrerasaurid, ornitho- = Thecodontosaurus pofyzelus (Hitchcock, 1865)

Parainfraclass Archosauria Cope, 1869 129 Sauropodomorpha von Huene, 1932 = Palaeosaurus fraserianus Cope, 1878 = Pachyspondylus orpenii Owen, 1854 [nomen dubium] [nomen dubium] = Clepsysaurus fraserianus (Cope, 1878) = Hortalotarsus skirtopodus Seeley, 1894 [nomen dubium] = Gyposaurus skirtopodus (Seeley, 1894) = Palaeosauriscus fraserianus(Cope , = Thecodontosaurus skirtopodus (Seeley, 1878) [nomen dubium] 1894) - Thecodontosaurus fraserianus(Cope , = Massospondylus browni Seeley, 1895 1878) [nomen dubium] [nomen dubium] = Anchisaums colurus Marsh, 1891 = Thecodontosaurus browni (Seeley, 1895) = Yaleosaurus colurus (Marsh, 1891) [nomen dubium] A. capensis (Broom, 1911) = Massospondylus harriesi Broom, 1911 = Gyposaurus capensis Broom, 1911 - Aetonyx palustris Broom, 1911 = Hortalotarsus s/drtopodus Broom, 1906 = Gryponyx africana Broom, 1911 non Seeley, 1894 = Gryponyx africanus Broom, 1911* A. sinensis (Young, 1941) Dong n. comb. = Gryponyx transvaalensis Broom, 1912 = Gyposaurus sinensis Young, 1941 [nomen dubium] NOTE: The above genus is organized ac­ = Aristosaurus erectus van Hoepen, 1920 cording to Galton, 1976, Galton & Cluver, = Gyposaurus erectus (van Hoepen, 1920) 1976, and Dong Z. (pers. comm.). Galton, 1976 = Dromicosaums gracilis van Hoepen, regards the differences between Anchisaums 1920 pofyzeius and Yaleosaurus colurus as due to sex­ = Gryponyx taylori Haughton, 1924 ual dimorphism, with A. pofyzeius the male and [nomen dubium] Y. colurus the female. = Massospondylus schwarzi Haughton, 1924 [nomen dubium] Genus: [To be described from the Lower = Thecodontosaurus dubius Haughton, Chinle Formation; Murry & Long, 1989] 1924 = Thecodontosaurus minor Haughton, 1924 non Haughton, 1918 Family: MASSOSPONDYUDAE = Gyposaurus capensis von Huene, 1932 von Huene, 1914 non Broom, 1911 = Gryponyx transvalensis von Huene, 1932 Census: 1 genus, 2 species (1 doubtful) [sic] = Gryponichidae Tatarinov, 1964 [sic] ?M. hislopi Lydekker, 1890 [nomen dubium] = Gryponychidae von Huene, 1932 [New species to be described from the Ka- yenta Formation of Arizona; skull de­ Genus: Massospondylus Owen, 1854 scribed in Crompton & Attridge, 1986] = Aetonyx Broom, 1911 = Aristosaurus van Hoepen, 1920 = Dromicosaums van Hoepen, 1920 Family: YUNNANOSAURIDAE = Gryponyx Broom, 1911 Young, 1942 = Leptospondylus Owen, 1854 [nomen dubium] Census: 1 genus, 1 species = Messospondylus Chinsamy, 1991 [sic] = Pachyspondylus Owen, 1854 [nomen Genus: Young, 1942 dubium] = Yuannanosaums Young, 1982 [sic] M. carinatus Owen, 1854 (Type) Y. huangi Young, 1942 (Type) = Plateosaums carinatus (Owen, 1854) = Yunnanosaurus robustus Young, 1951 = Leptospondylus capensis Owen, 1854 = Yuannanosaums robustas Young, 1982 [nomen dubium] [sic]

Sauropodomorpha von Huene, 1932 130 Mesozoic Meanderings #2 = Plateosaurus stormbergensis Broom, Family: PLATEOSAURIDAE Marsh, 1895 1915 [nomen dubium] = Plateosauravus stormbergensis (Broom, Census: 8 genera (1 doubtful), 1915) [nomen dubium] 8 species (1 doubtful) = Gigantoscelus molengraaffi van Hoepen, = Ammosauridae von Huene, 1914 1916 [nomen dubium] = Fulengidae Carroll & Galton, 1977 = molengraaffi (van = Plateosauriden von Huene, 1929 Hoepen, 1916) [nomen dubium] = Sellosauridae von Huene, 1908 = fortis van Hoepen, 1920 [nomen dubium] Genus: Ammosaums Marsh, 1891 = Euskelosaurus africanus Haughton, 1924 = Ammorsaums Stokes & Madsen, 1978 = Plateosaurus cullingworthi Haughton, [sic] 1924 A. major (Marsh, 1889) (Type) - Plateosauravus cullingworthi (Haughton, = Anchisaurus major Marsh, 1889 1924) = Anchisaurus solus Marsh, 1892 (juvenile) = Ammosaums solus (Marsh, 1892) Genus: Fulengia Carroll & Galton, 1977 (juvenile) [nomen dubium in Sereno, 1991] F. youngi Carroll & Galton, 1977 (Type) Genus: Lambert, 1983 NOTE: Originally classified as a "modern" = Coloradia Bonaparte, 1978/Blake, 1863 lizard in its own family Fulengidae, the above C. brevis (Bonaparte, 1978) (Type) genus and species are probably based on a = Coloradia brevis Bonaparte, 1978 hatchling or extremely young prosauropod Genus: Euskelosaurus Huxley, 1866 (Dong Z., pers. comm.; Sereno, 1991). = Enskelosaums Nopcsa, 1926 [sic] Genus: Lufengosaums Young, 1941 = Entelosaurus D. E. Russell, 1971 [sic] = Lufengocephalus Young, 1974 = Eucnemesaurus van Hoepen, 1920 = Lugengosaurus Carroll, 1987 [sic] [nomen dubium] = Lunfengosaurus Rozhdestvensky, 1965 = Euscelesaums Lydekker, 1890 [sic] [sic] = Euscelidosaurus Lydekker vide Nicholson = Tawasaums Young, 1982 (juvenile) & Lydekker, 1889 [sic] L. huenei Young, 1941 (Type) = Euscellosaurus Lydekker, 1890 [sic] = Lufengosaums magnus Young, 1942 = Euscelosawus Zittel, 1890 [sic] = Lufengocephalus tawae Young, 1974 = Euskelesaurus Huxley, 1867 [sic] = Tawasaums minor Young, 1982 = Euskelosaurs van Heerden, 1980 [sic] (juvenile) = Gigantoscelis von Huene, 1932 [sic] ?L. changduensis Zhao, 1986 [nomen nudum] = Gigantoscelus van Hoepen, 1916 [nomen NOTE: The genus Lufengocephalus, former­ dubium] ly classified as a , is apparently a se­ = Gigantoskelis Glut, 1972 [sic] nior synonym of Tawasaums (Dong Z., pers. = Orinosaums Lydekker, 1889 [nomen comm.) and thus a junior synonym of Lufengo­ dubium] saums. Sereno (1991) considers Tawasaums to = Orosaurus Huxley, 1867/Peters, 1862 be a nomen dubium classifiable only as Prosau- = Plateosauravus von Huene, 1932 ropoda indet. E. browni Huxley, 1866 (Type) = Orinosaums capensis Lydekker, 1889 Genus: Mussaums Bonaparte & Vince, 1979 [nomen dubium] = Mussasaums Olshevsky, 1978 [sic] = Euskelosaurus capensis (Lydekker, = Mussaums Bonaparte, 1978 [nomen 1889) [nomen dubium] nudum] = Orosaurus capensis (Lydekker, 1889) M. patagonicus Bonaparte & Vince, 1979 [nomen dubium] (Type)

Parainf raclass Archosauria Cope, 1869 131 Sauropodomorpha von Huene, 1932 = patagonicus Bonaparte, 1978 - Plateosaums erlenbergiensis von Huene, [nomen nudum] 1905 NOTE: The type specimen is a hatchling = Plateosaums omatus von Huene, 1905 prosauropod. An adult individual of this genus [nomen dubium] was described as Plateosaums sp. by Casami- = Plateosaums plieningeri von Huene, 1905 quela, 1980. = Gressfyosaurus plieningeri (von Huene, 1905) von Huene, 1926 Genus: Plateosaums von Meyer, 1837 = Plateosaums reinigeri von Huene, 1905 = Dimodosaurus Pidancet & Chopard, 1862 [nomen dubium] = Dinosaums Rutimeyer, 1856/Fischer de - Gressfyosaurus reinigeri (von Huene, Waldheim, 1847 1908) von Huene, 1926 [nomen dubium] = Greesfyosaurus Yadagiri, 1988 [sic] = Pachysauriscus reinigeri (von Huene, = Grestyosaurus Heilmann, 1927 [sic] 1908) Kuhn, 1959 [nomen dubium] = Gressfyosaurus Rutimeyer, 1857 = Pachysaums reinigeri (von Huene, 1908) = Pachysauriscus Kuhn, 1959 [nomen von Huene, 1932 [nomen dubium] dubium] = Gressfyosaurus torgeri Jaekel, 1911 - Pachysaurops von Huene, 1961 [sic] [nomen dubium] = Pachysaums von Huene, 1908/Fitzinger, = Plateosaums longiceps Jaekel, 1913 1843 = Plateosaums trossingensis E. Fraas, 1913 = Plataeosaurus von Meyer, 1845 [sic] = Plateosaums integer E. Fraas vide von = Plateosaums Yadagiri, 1988 [sic] Huene, 1915 [nomen nudum] = Platysaums Agassiz, 1846/Smith, 1844 [sic] = Pachysaums giganteus von Huene, 1932 P. engelhardti von Meyer, 1837 (Type) [nomen dubium] = Zanclodon laevis Plieninger, 1847 non = Gressfyosaurus giganteus (von Huene, Plieninger, 1846 1932) Steel, 1970 [nomen dubium] = Dinosaums gressfyi Rutimeyer, 1856 = Pachysauriscus giganteus (von Huene, = Gressfyosaurus ingens Rutimeyer, 1857 1932) Kuhn, 1959 [nomen dubium] = Dimodosaurus poiigniensis Pidancet & = Pachysaums wetzelianus von Huene, Chopard, 1862 1932 [nomen dubium] = Plateosaums poiigniensis (Pidancet & - Gressfyosaurus wetzelianus (von Huene, Chopard, 1862) von Huene, 1908 1932) Steel, 1970 [nomen dubium] = Zanclodon quenstedti Koken, 1900 = Pachysauriscus wetzelianus (von Huene, = Plateosaums quenstedti (Koken, 1900) 1932) Kuhn, 1959 [nomen dubium] = Gressfyosaurus robustus von Huene, = Plateosaums fraasianus von Huene, 1932 1908 [nomen dubium] NOTE: Synonymy within this genus is main­ = Plateosaums robustus (von Huene, ly according to Gallon (1984, 1985). Prelimina­ 1908) von Huene, 1932 [nomen dubium] ry morphometric analysis by Weishampel & = Pachysaums ajax von Huene, 1908 Chapman (1990) indicates that two or more [nomen dubium] species may be present. Further work is need­ = Gressfyosaurus ajax (von Huene, 1908) ed before they can be correctly named. [nomen dubium] = Pachysauriscus ajax (von Huene, 1908) Paragenus: Sellosaurus von Huene, 1908 Kuhn, 1959 [nomen dubium] = Gallon, 1973 (juvenile) = Pachysaums magnus von Huene, 1908 S. gracilis von Huene, 1908 (Type) [nomen dubium] = Plateosaums gracilis (von Huene, 1908) - Gressfyosaurus magnus (von Huene, = Thecodontosaums diagnostics E. 1908) Steel, 1970 [nomen dubium] Fraas, 1905 [nomen nudum] - Pachysauriscus magnus (von Huene, = Sellosaurus fraasi von Huene, 1908 1908) Kuhn, 1959 [nomen dubium] = Plateosaums fraasi (von Huene, 1908) = Teratosaurus minor von Huene, 1908

Sauropodomorpha von Huene, 1932 132 Mesozoic Meanderings #2 = Teratosaurus trossingensis von Huene, M. dayensis Zhao, 1986 (Type) 1908 Genus: Bonaparte, 1969 = Thecodontosawus hermannianus von = Strenusaurus Bonaparte, 1969 (juvenile) Huene, 1908 R. incertus Bonaparte, 1969 (Type) = Sellosaurus hermannianus (von Huene, = Strenusaurus procerus Bonaparte, 1969 1908) (juvenile) = Thecodontosaurus diagnosticus von Huene, 1932 Genus: Roccosaurus van Heerden vide Ander­ = Palaeosaurus diagnosticus (von Huene, son & Cruickshank, 1978 [nomen nudum] 1932) R. tetrasacralis van Heerden vide Kitching & = Palaeosauriscus diagnosticus (von Raath, 1984 (Type) Huene, 1932) NOTE: The above genus and species have = Efraasia diagnostica (von Huene, 1932) thus far been published only in faunal lists. The species may be a junior synonym of Melanoro- Genus: [To be described from the Upper Trias- saurus readi (P. Galton, pers. comm.). sic Dharmaram Formation of India; Kutty, 1969] Genus: Thotobolosaurus Ellenberger, 1972 [nomen nudum] T. mabeatae Ellenberger, 1972 (Type) Family: MELANOROSAURIDAE NOTE: The above genus is the "Maphut- von Huene, 1929 seng dinosaur" of Crompton & Charig, 1965. It is probably not a synonym of Euskelosaurus as Census: 3 genera, 3 species some workers have reported (J. S. Mcintosh, pers. comm.). = Plateosauravidae von Huene, 1932 Genus: [To be described from China; based on Genus: Galton, 1985 material originally referred to Sinosaurus; van C. borealis Galton, 1985 (Type) Heerden, 1978,1980] = Gresstyosaurus ingens Seeley, 1898 non Rutimeyer, 1857 Genus: [To be described from Argentina; Bona­ parte, 1986] Genus: Likhoelesaurus Ellenberger, 1972 [nomen nudum] L. ingens Ellenberger, 1972 (Type) Family: BLIKANASAURIDAE = Likhoelesaurus ferox Ellenberger, 1972 Galton & van Heerden, 1985 [nomen nudum] Genus: Haughton, 1924 Census: 1 genus, 1 species = Malanorosaurus Yadagjri, 1988 [sic] = Blikanosauridae Hunt, 1991 [sic] = Melanosaurus von Huene, 1954/Gilmore, 1927 [sic] Genus: Galton & van Heerden, = Melanososaurus Yadagiri, 1988 [sic] 1985 M. readi Haughton, 1924 (Type) = Blikanosaurus Hunt, 1991 [sic] B. cromptoni Galton & van Heerden, 1985 Genus: Microdontosaurus Zhao, 1983 [nomen (Type) nudum]

Parainfraclass Archosauria Cope, 1869 133 Sauropodomorpha von Huene, 1932 Notes and New Taxa

Sauropodomorpha von Huene, 1932 134 Mesozoic Meanderings #2 Superorden Sauropodomorpha von Huene, 1932 (continued)

Orden Brontosauria nov. (continued) Suborder: Sauropoda Marsh, 1878 Census: 9 families, 73 genera (16 doubtful), 122 species (35 doubtful) K. yamanpalliensis Yadagiri, 1988 (Type) Family: BARAPASAURIDAE = yamanpalliensis Yadagiri, L B. Halstead & J. Halstead, 1981 1986 [nomen nudum] = Kotasaurus yemanpalliensis Yadagiri, Census: 5 genera, 5 species 1988 [sic] = Cooper, 1984 Genus: Kunmingosaurus Zhao, 1986 [nomen nu­ Genus: Jain, Kutty, Roy-Chow- dum] dhury & Chatterjee, 1975 = Kunmingosaurus Zhen, Li & Rao, 1986 = Barapasums Yadagiri, 1988 [sic] [nomen nudum] = Basapasaurus Chow, 1979 [sic] K utingensis Zhao, 1986 (Type) B. tagorei Jain, Kutty, Roy-Chowdhury & = Kunmingosaurus utingensjs Zhao, 1986 Chatterjee, 1975 (Type) [sic] = Kunmingosaurus utingi Zhen, Li & Rao, Genus: Zhao, 1986 [no- 1986 [nomen nudum] men nudum] =» Kunmingosaurus wudingi Zhao, 1986 = Chinshakiangosaurus Yeh, 1975 [nomen [sic] nudum] = Kunmingosaurus wudingensis C. zhongheensis Zhao, 1986 (Type) [Anonymous] 1990 [nomen nudum] = Chinshakiangosaurus chunghoensis Yeh, NOTE: The above genus remains unde- 1975 [nomen nudum] scribed, but a photograph of its hind limb and = Chinshakiangosaurus zhonghonensis pelvis was published by Zhao (1986), and its en­ Zhao, 1986 [sic] tire skeleton appeared in 77ie Age of Dinosaurs NOTE: The above genus remains unde- in Japan and China (Dong, Hasegawa & Azu- scribed, but a photograph of its femur was pub­ ma, 1990), a Japanese dinosaur exhibition lished by Zhao (1986). Referred to this family guidebook (title transliterated by M. Tanimoto, provisionally. pers. comm.). Referred to this family provisio­ Genus: Kotasaurus Yadagiri, 1988 nally. = Kotasaurus Yadagiri, 1986 [nomen Genus: Ohmdenosaurus Wild, 1978 nudum] O. liasicus Wild, 1978 (Type) = Kotasautus Yadagiri, 1988 [sic] = Ohmdenosaurus liassicus Yadagiri, 1988 = Kotasurus Yadagiri, 1988 [sic] [sic]

Parainfraclass Archosauria Cope, 1869 135 Sauropodomorpha von Huene, 1932 Genus: Raath, 1972 NOTE: The above genus and species are = Volcondon Dong, 1990 [sic] based on a sauropod tooth probably but not = Vulcanodon Yadagiri, 1988 [sic] certainly referable to Cetiosaums. = Vulcandon Yadagiri, 1988 [sic] Genus: Cetiosaums Owen, 1842 V. karibaensis Raath, 1972 (Type) = Ceteosaurus Phillips, 1871 [sic] Genus: Zizhongosaurus Dong, Zhou & Zhang, C. medius Owen, 1842 1983 = Cetiosaums hypoolithicus Owen, 1842 = Zizhongosaurus Mcintosh, 1990 [sic] [nomen oblitum] Z. chuanchengensis Dong, Zhou & Zhang, = Cetiosaums hypooolithicus Olshevsky, 1983 (Type) 1978 [sic] = Zizhongosaurus chuanchensis Dong, C. oxoniensis Phillips, 1871 (Type) Zhou & Zhang, 1983 [sic] = Cetiosaums giganteus Owen vide Hux­ ley, 1870 [nomen oblitum] ?C. mogrebiensis de Lapparent, 1955 Parafamily: CETIOSAURIDAE Genus: Dachungosaums Zhao, 1986 [nomen nu­ Lydekker, 1888 dum] = Dachongosaums Zhao, 1986 [sic] Census: 11 genera (1 doubtful), D. yunnanensis Zhao, 1986 (Type) 14 species (1 doubtful) NOTE: The above genus remains unde- = Bellusaurinae Dong, 1986 scribed, but a photograph of its remains in situ [nomen nudum] was published by Zhao (1986). Referred to this = Bellusaurinae Dong, 1990 family provisionally. = Cardiodontidae Lydekker, 1895 Genus: Datousaums Dong & Tang, 1984 = Cetiosaurinae Janensch, 1929 = Datousaums Dong,'1983 [nomen nudum] = Shunosaurinae Mcintosh, 1990 = Lancangosaums Dong, Zhou & Zhang, Genus: Cabrera, 1947 1983 [nomen nudum] = Amigdalodon Bonaparte, 1978 [sic] D. bashanensis Dong & Tang, 1984 (Type) A. patagpnicus Cabrera, 1947 (Type) = Datousaums bashanensis Dong, 1983 [nomen nudum] Genus: Longman, 1933 A. mckillopi Longman, 1933 (Type) Genus: Haplocanthosaums Hatcher, 1903 NOTE: The above genus is referred to this =» Haplocanthosaums von Huene, 1909 [sic] family provisionally (R: E. Molnar, pers. = Haplocanthus Hatcher, 1903/Agassiz, coram.). 1845 (as Haplocanthus; Haplocanthosaums conserved in Lucas & Hunt, 1989 [ICZN Genus: Bellusaums Dong, 1990 Case #2684] and ICZN Opinion #1633) = Bellusaums Dong, 1986 [nomen nudum] = Harlocanthosaurus Yadagiri, 1988 [sic] B. sui Dong, 1990 (Type) H. priscus (Hatcher, 1903) (Type) = Bellusaums sui Dong, 1986 [nomen = Haplocanthus priscus Hatcher, 1903 nudum] = Morosaums agilis Marsh, 1889 [nomen NOTE: Initially classified as a brachiosau- aubium] rid, the above genus is probably a cetiosaurid = Camarasaums agilis (Marsh, 1889) (J. S. Mcintosh, pers. coram.). [nomen aubium] Genus: Cardiodon Owen, 1841 [nomen = Haplocanthosaums utterbacki Hatcher, aubium; = Cetiosaums?] 1903 C. rugulosus Owen, 1845 (Type) = Haplocanthus utterbacki Olshevsky, = Cetiosaums rugulosus (Owen, 1845) 1978 [sic] [nomen aubium] = Haplocanthosaums piscus Yadagiri, 1988 [sic]

Sauropodomorpha von Huene, 1932 Mesozoic Meanderings #2 H. delfsi Mcintosh & Williams, 1988 Genus: [To be described from the Bathoman of Genus: Lancangjiangosaums Zhao, 1983 [no- Morocco; a large cetiosaurid presently re­ men nudum] ferred to Cetiosaums mogrebiensis; Taquet & = Lancanjiangosaurus Zhao, 1986 [nomen Monbaron, 1981; Mcintosh, 1990] nudum] L. cachuensis Zhao, 1986 (Type) NOTE: The above genus remains unde- Family: BRACHIOSAURIDAE scribed, but a photograph of its remains in situ Riggs, 1904 was published by Zhao (1986). Referred to this family provisionally. Census: 12 genera (2 doubtful), 21 species (9 doubtful) Genus: Oshanosaums Zhao, 1986 [nomen nu­ dum] = Astrodontidae von Huene, 1948 O. youngi Zhao, 1986 (Type) = Astrodontinae von Huene, 1932 NOTE: The above genus remains unde- = Bothriospondylidae Lydekker, 1895 scribed, appearing in a faunai list in Zhao, [nomen oblitum] 1986. Referred to this family provisionally. = Brachiosaurinae Janensch, 1929 = Pleurocoelidae Marsh, 1888 Genus: Bonaparte, 1979 [nomen oblitum] P. fariasi Bonaparte, 1979 (Type) Genus: Johnston, 1859 Genus: Protognathosaums nov. = Astrodonius Kuhn, 1961 = Protognathus Zhang, 1988/Basilewsky, = Astrodontonius Steel, 1970 [sic] 1950 = Astrond Dong, 1990 [sic] P. axyodon (Zhang, 1988) n. comb. (Type) = Astrood Dong, 1990 [sic] = Protognathus axyodon Zhang, 1988 A. johnstoni Leidy, 1865 (Type) NOTE: The generic name Protognathosau­ = Astrodonius johnstoni (Leidy, 1865) rus is proposed to replace the name Protognath­ us, which is preoccupied by the name of a Genus: Owen, 1875 beetle. = Marmarospondylus Owen, 1875 [nomen dubium] Genus: Rhoetosaums Longman, 192S B. suffbsus Owen, 1875 (Type) = Rhoetosaums de Lapparent & Lavocat, = Pleurocoelus suffosus (Owen, 1875) 1955 [sic] Marsh, 1897 = Rheteosaurus Yadagiri, Prasad & Satsan- ?B. robustus (Owen, 1875) [nomen dubium] gi, 1979 [sic] = Marmarospondylus robustus Owen, 1875 R. brownei Longman, 1925 (Type) [nomen dubium] Genus: Shunosaums Dong, Zhou & Zhang, ?B. madagascariensis Lydekker, 1895 1983 [nomen dubium] = Shunosaums Dong, 1980 [sic] NOTE: Material referred to this species, = Shunosaums Dong, 1981 [nomen nudum] considered indeterminate by Mcintosh, 1990, - Shuosaurus Chow, 1979 [nomen nudum] was made the type specimen of the cetiosaurid S. Hi Dong, Zhou & Zhang, 1983 (Type) Lapparentosaums madagascariensis. = Shuosaurus Hi Dong, 1980 [nomen Genus: Brachiosaurus Riggs, 1903 nudum] = Brachyosaurus Langston, 1974 [sic] S. ziliujingensis [Anonymous] 1986 [nomen - Branchiosaurus Yadagiri, 1988 [sic] nudum; to be described by Zhang] B. altithorax Riggs, 1903 (Type) = Brachiosaurus (Brachiosaurus) altithorax (Riggs, 1903) = Brachiosaurus alius Jensen, 1986 [sic]

Parainfraclass Archosauria Cope, 1869 137 Sauropodomorpha von Huene, 1932 IB. atalaiensis de Lapparent & Zbyszewski, Genus: Bonaparte, 1986 1957 L. madagascariensis Bonaparte, 1986 (Type) = Brachiosaurus ataliensis Paul, 1988 [sic] NOTE: See note for Bothriospondylus mada­ = Branchiosaurus atalaiensis Yadagiri, gascariensis. 1988 [sic] Genus: Pelomsaurus Mantell, 1850 ?B. nougaredi de Lapparent, 1960 = Seeley, 1869 [nomen NOTE: See note for Giraffatitan. dubium] Genus: Damalasaums Zhao, 1983 [nomen nu­ = Hoplosaurus Lydekker, 1890/Seeley, 1881 dum] [sic] = Damalasaums Zhao, 1986 [nomen nu­ = Ischymsaurus Hulke, 1874/Cope, 1869 dum] [nomen dubium] D. laticostalis Zhao, 1986 (Type) = Morinosaurus Sauvage, 1874 [nomen D. magnus Zhao, 1986 [nomen nudum] dubium] = Neosodon de la Moussaye, 1885 [nomen Genus: Dinodocus Owen, 1884 [nomen dubium] dubium; = Pelomsaurus?] = Nesodon Dollo, 1885 vide Nopcsa, D. mackesoni Owen, 1884 (Type) 1926/Owen, 1840 [sic] = Pelomsaurus mackesoni (Owen, 1884) = Oplosaurus Gervais, 1852 [nomen [nomen dubium] dubium] NOTE: Referred to this family provisional­ ly, may be a synonym of Pelomsaurus or some = Ormithopsis Sauvage, 1897/8 [sic] other brachiosaurid (R. E. Molnar, pers. • = Omithopsis Seeley, 1870 [nomen dubium] comm.; Mcintosh, 1990). = Pelemsaurus Galton, 1980 [sic] = Pelosaurus Fischer, 1989 [sic] Genus: Dystylosaurus Jensen, 1985 = Pelmmsaurus Delair, 1959 [sic] D. edwini Jensen, 1985 (Type) = Polomsaurus Seeley, 1869 [sic] NOTE: This genus is referred to the Brachi- = Teiomsaurus Baur, 1891 [sic] osauridae in Paul, 1988 and Mcintosh, 1990. J. P. conybearei Mantell, 1850 (Type) A. Jensen (pers. comm.), however, considers it = brevis Owen, 1842 [nomen distinctive enough to warrant its own family. dubium] = Momsaurus brevis (Owen, 1842) [nomen Genus: Giraffatitan Paul, 1988 [nomen novum dubium] ex subgenem] = Cetiosaurus conybearei Melville, 1849- - Giraffatitan PauL 1987 [nomen nudum] 50 [nomen dubium] G. brancai (Janensch, 1914) n. comb. (Type) = Oplosaurus armatus Gervais, 1852 = Brachiosaurus brancai Janensch, 1914 [nomen dubium] = Brachiosaurus (Giraffatitan) brancai (Janensch, 1914) PauL 1988 = Hoplosaurus armatus (Gervais, 1852) = Cetiosaurus brancai (Janensch, 1914) [nomen dubium] Yadagiri, 1988 [sic] - Oplosaurus arcuatus Gervais, 1853 [sic] = Omithopsis hulkei Seeley, 1870 [nomen = brancai (Janensch, 1914) dubium] Lambrecht, 1933 [sic] = Pelomsaurus hulkei (Seeley, 1870) = Brachiosaurus fraasi Janensch, 1914 [nomen dubium] NOTE: The above genus, initially described as a subgenus of Brachiosaurus, is separable = Bothriospondylus elongatus Owen, 1875 therefrom on the basis of the vertebral column [nomen dubium] figured by Paul (1988). J. S. Mcintosh (pers. = Bothriospondylus magnus Owen, 1875 comm.) does not believe the differences are ge­ [nomen dubium] netically significant. = Chondmsteosaurus magnus (Owen, 1875) [nomen dubium]

Sauropodomorpha von Huene, 1932 138 Mesozoic Meanderings #2 = Pleurocoelus valdensis Lydekker, 1889 P. nanus Marsh, 1888 (Type; juvenile) [nomen dubium] = Astrodon nanus (Marsh, 1888) (juvenile) = Astrodon valdensis (Lydekker, 1889) = Pleurocoelus alius Marsh, 1888 (adult) [nomen dubium] = Astrodon altus (Marsh, 1888) (adult) ?P. becklesii Manteil, 1852 [nomen dubium] Genus: Ultrasauros nov. = becklesi Manteil, 1852 = Ultrasaurus Jensen, 1978 [nomen nudum] [nomen dubium]* = Ultrasaurus Jensen, 1985/Kim, 1983 = Morosaums becklesi (Manteil, 1852) U. macintoshi (Jensen, 1985) n. comb. (Type) Marsh, 1889 = Ultrasaurus macintoshi Jensen, 1985 ?P. megalonyx (Seeley, 1869) [nomen = Ultrasaurus mcintoshi Miller, Baer, dubium] Stadtman & Britt, 1991 [sic] - Gigantosaums megalonyx Seeley, 1869 NOTE: The above generic name is pro­ [nomen dubium] posed to replace Ultrasaurus Jensen, 1985, ?P. humerocristatus (Hulke, 1874) [nomen which is preoccupied by Ultrasaurus Kim, 1983. dubium] Paul, 1988 synonymizes this genus with Brachio­ = Cetiosaurus humerocristatus Hulke, 1874 saums, but the type dorsal vertebra of Ultrasau­ [nomen dubium] ros as figured therein is too dissimilar from the = humerocristatus (Hulke, dorsal vertebrae of Brachiosaums altithorax to 1874) [nomen dubium] warrant synonymy. The genera are best kept - Pelosaurus humerocristatus (Hulke, separate pending further work. 1874) Fischer, 1989 [sic] = Iguanodon praecursor Sauvage, 1876 Genus: Ultrasaurus Kim, 1983 [nomen dubium] [nomen dubium] - Ultrasaurus Kim, 1979 [nomen nudum] = Caulodon praecursor (Sauvage, 1876) U. tabriensis Kim, 1983 (Type) [nomen dubium] NOTE: The above genus is referred to this = Neosodon praecursor (Sauvage, 1876) family provisionally. [nomen dubium] Genus: Bonaparte, 1979 - Pelorosaurus praecursor (Sauvage, 1876) = Voekeimeria Yadagiri, 1988 [sic] [nomen dubium] = Volkherimeria Czerkas & Czerkas, 1990 = Neosodon de la Moussaye, 1885 (no [sic] specific name assigned) V. chubutensis Bonaparte, 1979 (Type) ?P. manseli (Hulke, 1874) [nomen dubium] = Voekeimeria chulbutensis Yadagiri, 1988 = Ischyrosaurus manseli Hulke, 1874 vide [sic] Lydekker, 1888 [nomen dubium] = Ornithopsis manseli (Hulke, 1874) Genus: [To be described; the "Hughenden sau­ [nomen dubium] ropod," a large Lower Cretaceous ?brachio- - Morinosaurus typus Sauvage, 1874 saurid from Australia; Molnar, 1980] [nomen dubium] ?P. leedsi (Hulke, 1887) [nomen dubium] Genus: [To be described from the Morrison = Ornithopsis leedsi Hulke, 1887 [nomen Formation; a "sauropod with four pedal ungu­ dubium] als," perhaps just a new species of Pleurocoel­ us; Gallon & Jensen, 1973] - leedsi (Hulke, 1887) [nomen dubium] Genus: [To be described from the Lower Creta­ = Cetiosaurus leedsi (Hulke, 1887) [nomen ceous of Montana; the "Cloverly sauropod," dubium] perhaps just a new species of Pleurocoelus; Ostrom, 1970] Genus: Pleurocoelus Marsh, 1888 ( = Astro­ don?) Genus: [To be described from France; initially = Plaurocoelus Langston, 1974 [sic] referred to Bothriospondylus madagascariensis = Pleurocoelus Sauvage, 1897/8 [sic]

Parainfraclass Archosauria Cope, 1869 139 Sauropodomorpha von Huene, 1932 (Dorlodot, 1934; Lapparent, 1943) but prob­ = leptodints Cope, 1879 ably represents a new genus; Mcintosh, 1990] [nomen dubium] » Pleurocoelus montanus Marsh, 1896 (juvenile) Family: CAMARASAURIDAE Cope, 1877 = Astrodon montanus (Marsh, 1896) (juvenile) Census: 7 genera (2 doubtful), = altus Berman & Mcin­ 11 species (3 doubtful) tosh, 1978 [sic; err. for Amphicoelias latus Cope, 1877] = Camarasaurinae Nopcsa, 1928 C. grandis (Marsh, 1877) = Morosauridae Marsh, 1882 = grandis Marsh, 1877 = Opisthocoelicaudiinae Mcintosh, 1990 = Morosaums grandis (Marsh, 1877) Genus: Algoasawus Broom, 1904 = Morosaums impar Marsh, 1878 A. bauri Broom, 1904 (Type) = Camarosaums impar (Marsh, 1878) = Morosaums robustus Marsh, 1878 Genus: Aragosaums Sanz, Buscalioni, Casano- [nomen dubium] vas & Santafe, 1987 = Camarasaurus robustus (Marsh, 1878) A. ischiaticus Sanz, Buscalioni, Casanovas & [nomen dubium] Santafe, 1987 (Type) C. lentus (Marsh, 1889) Genus: Asiatosaums Osborn, 1924 [nomen = Morosaums lentus Marsh, 1889 dubium] - Uintasaurus douglassi Holland, 1919 = Asitosaurus Kalandadze & Kurzanov, - Camarasaurus douglassi (Holland, 1919) 1973 [sic] = Camarosaums annae Ellinger, 1950 A. mongoliensis Osborn, 1924 (Type) = Camarasaurus annae (Ellinger, 1950) = Asiatosaums mongolicus Young, 1937 ?C. alenquerensis (de Lapparent & Zbyszew­ [sic] ski, 1957) A. kwangshiensis Hou, Yeh & Zhao, 1975 =Apatosaurus alenquerensis de Lapparent [nomen dubium] & Zbyszewski, 1957 = Atlantosaums alenquerensis (de Lap- Genus: Camarasaurus Cope, 1877 parent & Zbyszewski, 1957) = Camacasaums Young, 1958 [sic] = Brontosaums alenquerensis (de Lap- = Camaeosaurus Cope, 1877 [sic] parent & Zbyszewski, 1957) = Camarasuams Berman & Mcintosh, 1978 [sic] Genus: Cathetosaunis Jensen, 1988 (= Camara­ = Camarosaums Riggs, 1901 [sic] saurus?) = Camasaums Mcintosh, 1977 [sic] = Cathetosaunis Jensen, 1987 [nomen - Camerasaums Colbert, 1951 [sic] nudum] = Caulodon Cope, 1877 [nomen dubium] C. lewisi Jensen, 1988 (Type) - Monosaums Berman & Mcintosh, 1978 = Cathetosaunis lewisi Jensen, 1987 [sic] [nomen nudum] - Morasaums Riggs, 1904 [sic] Genus: Chondrosteosaunis Owen, 1876 [nomen - Morosaums Marsh, 1878 dubium] = Uintasaurus Holland, 1919 — Chondrosteus von Huene, 1907/8 C. supremus Cope, 1877 (Type) [«c]/Agassiz, 1833-44 = Amphicoelias latus Cope, 1877 = Eucamarotus von Huene, 1909 [sic] (juvenile?) = Eucamerotes Rozhdestvensky & = Caulodon diversidens Cope, 1877 Tatarinov, 1964 [51c] [nomen dubium] = Hulke, 1872 [nomen = Caulodon leptoganus Cope, 1878 dubium] [nomen dubium] C. gigas Owen, 1876 (Type)

Sauropodomorpha von Huene, 1932 140 Mesozoic Meanderings #2 = Chondrosteus gigas (Owen, 1876) [sic] Genus: "Klamelisaurus" [to be described by = Eucamerotus Hulke, 1872 [nomen Zhao C. C. from the Late Jurassic of the dubium; no specific name assigned] Dzungar Basin, ; known from a skele­ = Omithopsis eucamerotus Hulke, 1882 ton about 80% complete; SVP Bulletin #149: [nomen dubium] 45] = valdensis von Huene, 1929 "K. gobiensis" [type species to be described] [nomen dubium] Genus: Young, 1954 = Chondrosteosaurus megaius Fox vide = Mamenchiosaurus Dong, 1980 [sic] Blows, 1983 [nomen oblitum] = Mammenchisaurus Czerkas & Czerkas, Genus: Borsuk-Bialynicka, 1990 [sic] 1977 = Manenchisaurus Young, 1954 [sic] = Opisthocoelocaudia Carroll, 1987 [sic] = "Moshisaurus" Hisa, 1988 [nomen nudum O. skarzynsku Borsuk-Bialynicka, 1977 in Utan Scientific Magazine #4: 24] (Type) M. constructus Young, 1954 (Type) ?M. hochuanensis Young & Chao, 1972 = Mamenchisaurus hochuanensis Family: Kuhn, 1965 [Anonymous] 1965 [nomen nudum] NOTE: This species of Mamenchisaurus Census: 5 genera (1 doubtful), could well belong to a different genus. Its 10 species (1 doubtful) postcramal skeleton, reconstructed in Young & Chao, 1972, shows numerous differences from = Euhelopodinae Romer, 1956 that of the type species. = Helopodinae von Huene, 1932 [New species to be described from the Up­ = Young & Chao, 1972 per Jurassic of Chengdu; M. Tanimoto, = Mamenchisaurinae Mcintosh, 1990 pers. comm.] Genus: Chiayusaurus Bohlin, 1953 [nomen NOTE: Sauropod remains nicknamed "Mo­ dubium] shisaurus" or "Moshi-ryu" in a Japanese popu­ = Chiayusaurus Bohlin, 1953 [nomen lar-science article were referred to Mamenchi­ dubium]* saurus sp. by Hasegawa, Manabe, Hanai, Kase & Oji (1991). = Chiayasaurus Dong, 1977 [sic] = Chiayausaurus Dong, 1977 [sic] Genus: Young, 1939 = Chiayiisaurus Rozhdestvensky & = Omeiosaurus Gallon, 1986 [sic] Tatarinov, 1964 [sic] = Zigongosaurus Hou, Chao & Chu, 1976 = Chiayuesaurus Young, 1958 [sic] O. junghsiensis Young, 1939 (Type) = Chiryuesaurus Young, 1958 [sic] = Omeisaurus yunghsiensis Young, 1939 C. lacustris Bohlin, 1953 (Type) [sic] = Chiayusaurus lacustris Bohlin, 1953 = Omeisaurus junghsienensis Young, 1958 [nomen dubium]'' [sic] = Chiayasaurus laciatain Dong, 1977 [sic] - Omeisaurus jungshiensis Dong, 1987 [sic] Genus: Romer, 1956 O. changshouensis Young, 1958 = Eohelopus Rozhdestvensky, 1977 [sic] O.fwdensis (Hou, Chao & Chu, 1976) = Helopus Wiman, 1929/Wagler, 1832 = Zigongosaurus fuxiensis Hou, Chao & E. zdanskyi (Wiman, 1929) (Type) Chu, 1976 = Helopus zdanskyi Wiman, 1929 = Omeisaurus fuxiensis Dong, Zhou & Zhang, 1983 O. tianfuensis He, Li, Cai & Gao, 1984 ?0. zigongensis Tanimoto, 1988 [nomen nudum] O. luoquanensis Li vide He, Li & Cai, 1988

Parainfraclass Archosauria Cope, 1869 141 Sauropodomorpha von Huene, 1932 Genus: Tienshanosaurus Young, 1937 = Elosaurus Peterson & Gilmore, 1902 = Teinshanosaurus Dong, 1979 [sic] (juvenile) = Tienschanosaurus Rozhdestvensky, 1977 A. ajax Marsh, 1877 (Type) [sic] = ajax (Marsh, 1877) T. chitaiensis Young, 1937 [sic] = Atlantosaurus immanis Marsh, 1878 = Apatosaurus laticollis Marsh, 1879 Genus: [To be described from China by D. A. = Atlantosaurus laticollis (Marsh, 1879) Russell and Zheng Z.; one or more very large A. excelsus (Marsh, 1879) (some estimated to be over 30 meters long) = excelsus Marsh, 1879 sauropods, including one new genus with asso­ = Atlantosaurus excelsus (Marsh, 1879) ciated cranial material and distinctive, slen­ = Brontosaurus amplus Marsh, 1881 der posterior with a cervi­ = Apatosaurus amplus (Marsh, 1881) cal ribs over 3 meters long; D. A. Russell, = Atlantosaurus amplus (Marsh, 1881) pers. comm.] = Elosaurus parvus Peterson & Gilmore, 1902 (juvenile) A. louisae Holland, 1915 Family: DIPLODOCIDAE Marsh, 1884 = Atlantosaurus louisae (Holland, 1915) = Brontosaurus louisae (Holland, 1915) Census: 10 genera (3 doubtful), ?A. minimus Mook, 1917 21 species (6 doubtful) = Atlantosaurus minimus (Mook, 1917) = Amphicoeliidae Cope, 1877 NOTE: The above species may represent a [nomen oblitum] new genus of cetiosaurid (Mcintosh, 1990). = Apatosauridae von Huene, 1927 Genus: Atlantosaurus Marsh, 1877 [nomen = Apatosaurinae Janensch, 1929 dubium] = Atlantosauridae Marsh, 1877 = Titanosaurus Marsh, 1877/Lydekker, 1877 [nomen oblitum] A. montanus (Marsh, 1877) (Type) - Atlantosaurinae Steel, 1970 = Titanosaurus montanus Marsh, 1877 = Diplodocinae Janensch, 1929 [nomen dubium] = Trtanosauridae Marsh, 1895/ Lydekker, 1885 Genus: Marsh, 1890 (= Amphi­ coelias?) Genus: Amphicoelias Cope, 1877 B. lentus Marsh, 1890 (Type) = Amphicdelias Hou, Yeh & Zhao, 1975 = Barosaurus affinis Marsh, 1899 [nomen [sic] dubium] A. altus Cope, 1877 (Type) = Amphicoelias fragillimus Cope, 1878 Genus: Cetiosauriscus von Huene, 1927 = Amphicoelias fragillissimus Cope, 1881 ?C. longus (Owen, 1842) [nomen dubium] [sic] = Cetiosaurus longus Owen, 1842 [nomen dubium] Genus: Apatosaurus Marsh, 1877 = Cetiosaurus epioolithicus Owen, 1842 = Apatosanrus Yadagiri, 1988 [sic] [nomen oblitum] = Apatosausus Dong, 1979 [sic] ?C. gfymptonensis (Phillips, 1871) [nomen = Bronotosaurus Langston, 1974 [sic] dubium] = Brontosaurus Mcintosh & Berman, 1975 - Cetiosaurus glymptonensis Phillips, 1871 [sic] [nomen dubium] - Brontosaurus Marsh, 1879 ?C. greppini (von Huene, 1922) = Brontsaurus Stokes, 1988 [sic] = Omithopsis greppini von Huene, 1922 = Cetiosaurus greppini (von Huene, 1922) C. stewarti Charig, 1980 (Type)

Sauropodomorpha von Huene, 1932 142 Mesozoic Meanderings #2 = Cetiosaunts leedsi von Huene, 1927 non NOTE: Tomieria africana is almost certainly (Hulke, 1887) a diplodocid, but Tomieria dixeyi probably rep­ resents a new genus of titanosaurid (R. E. Mol- Genus: Marsh, 1878 nar, pers. comm.; Mcintosh, 1990). Mcintosh = Dipiodocus Yadagiri, 1988 [sic] (1990), however, conservatively retains Tomier­ D. longus Marsh, 1878 (Type) ia in the Titanosaundae. Wild (1991) proposed D. lacustris Marsh, 1884 [nomen dubium] the genus for the species Tomieria D. camegii Hatcher, 1901 robusta, presently regarded as a titanosaurid. = Dipiodocus camegiei Holland, 1906 [sic] D. hayi Holland, 1924 Genus: [To be described from the Morrison Formation by J. A. Jensen; the description Genus: Cope, 1877 [nomen may not appear in the near future; J. S. Mc­ dubium] intosh, pers. comm.] D. viaemalae Cope, 1877 (Type) Genus: Megacervixosaums Zhao, 1983 [nomen nudum] Family: DICRAEOSAURIDAE M. tibetensis Zhao, 1986 (Type) von Huene, 1956 Genus: Mongoiosaurus Gilmore, 1933 [nomen Census: 5 genera, 8 species (1 doubtful) dubium] M. hapiodon Gilmore, 1933 (Type) = Dicraeosaurinae Janensch, 1929 = Mongoiosaurus hoplodon Young, 1937 [sic] Genus: Salgado & Bonaparte, 1991 Genus: "Seismosaurus" Gillette, 1986 [to be de­ = Amargasaurus Bonaparte, 1984 [nomen scribed from the Morrison Formation of New nudum] Mexico; a very large diplodocid; the generic - Amargasaurus Bonaparte, 1990 [nomen name was published in numerous newspaper nudum] accounts in 1986 and in an article by I. Ander­ = Amargosaurus Mcintosh, 1989 [sic] son in New Scientist, April 23, 1987: 24] A. cazaui Salgado & Bonaparte, 1991 (Type) Genus: Supersaurus Jensen, 1985 = Amargasaurus groeberi Bonaparte, 1984 = Supersaurus Jensen, 1972 [nomen nudum] [nomen nudum] S. vivianae Jensen, 1985 (Type) = Amargasaurus cazaui Bonaparte, 1990 NOTE: Paul, 1988 suggests that this genus is [nomen nudum] a junior synonym oiBarosaurus. Genus: Dicraeosaurus Janensch, 1914 Genus: Tomieria Sternfeld, 1911 = Dicraeosaums Yadagiri, 1988 [sic] = Gigantosaurus E. Fraas, 1908/Seeley, 1869 = Dicreaosaurus Swinton, 1970 [sic] T. africana (E. Fraas, 1908) Sternfeld, 1911 = Dicreosaurus Borsuk-Bialynicka, 1977 [sic] (Type) = Dikraeosaurus Lull, 1924 [sic] = Gigantosaurus africanus E. Fraas, 1908 D. hansemanni Janensch, 1914 (Type) = Barosaurus africanus (E. Fraas, 1908) D. sattleri Janensch, 1914 T. gracilis (D. A. Russell, Beland & Genus: Nowinski, 1971 Mcintosh, 1980) n. comb. N. mongoliensis Nowinski, 1971 (Type) = Barosaurus gracilis D. A. Russell, N. pachi Dong, 1977 [nomen dubium] Beland & Mcintosh, 1980 = Barosaurus africanus var. gracilis Genus: Kurzanov & Bannikov, Janensch, 1961 1983 (= Nemegtosaurus?) ?T. dixeyi (Haughton, 1928) = Questiosaurus Tatarinov, 1982 [sic] = Gigantosaurus dixeyi Haughton, 1928 = Questosaurus Carroll, 1987 [sic]

Parairtfraclass Archosauria Cope, 1869 143 Sauropodomorpha von Huene, 1932 Q. orientalis Kurzanov & Bannikov, 1983 A. rionegrinus J. Powell, 1987 (Type) (Type) = rionegrinus J. Powell, 1986 [nomen nudum] Genus: Rebbachisaums Lavocat, 19S4 = Eolosaurus rionegrinus J. Powell vide R. garasbae Lavocat, 1954 (Type) Bonaparte, 1985 [sic] R. tamesnensis de Lapparent, 1960 NOTE: The above genus and species were NOTE: The above genus probably repre­ described in J. Powell's doctoral dissertation; a sents a new family of sauropods (Mcintosh, brief description was published by Powell in 1990) and is referred to this family provisional­ 1987. ly- Genus: Aepisaurus Gervais, 1852 [nomen Genus: [To be described from the Late Creta­ dubium] ceous of Mongolia; based on postcranial re­ = Aeposaurus Romer, 1966 [sic] mains presently on display at the Paleontologi- = Aepyosaurus von Huene, 1932 [sic] cal Institute of the USSR Academy of Scienc­ = Aepysaurus Gervais, 1859 [sic] es; may prove to be Quaesitosaunts or Nemeg- A. elephantinus Gervais, 1852 (Type) tosaunis; P. Currie, pers. coram.] Genus: Gilmore, 1922 A. sanjuanensis Gilmore, 1922 (Type) Family: T1TANOSAURIDAE Genus: von Huene, 1927 Lydekker, 1885 = Anarctosaurus Janensch, 1935 [sic] = Anctartosaurus [Anonymous] 1977 [sic; in Census: 16 genera (6 doubtful), Die Geheimnisse der Urzeit 3, p. 234] 30 species (13 doubtful) A. wichmannianus von Huene, 1929 (Type) = Antarctosauridae Olshevsky, 1978 ?A. giganteus von Huene, 1929 = Antarctosaurinae J. Powell, 1986 vide ?A. septentrionalis von Huene, 1932 Bonaparte, 1987 ?A. jaxarticus Riabinin, 1938 [nomen aubium] - Argyrosaurinae J. Powell, 1986 vide = Antarctosaurus jaxartensis Kuhn, 1965 Bonaparte, 1987 [sic] = Sattasaurinae J. Powell, 1986 vide ?A. brasiliensis Arid & Vizotto, 1972 Bonaparte, 1987 Genus: Lydekker, 1893 = Tttanosaurinae Nopcsa, 1928 = Argirosaurus Sanz, Casanovas & Santafe, NOTE: This family has become a "grab- 1982 [sic] bag" for Cretaceous sauropod genera based on A. superbus Lydekker, 1893 (Type) fragmentary remains. Work in progress by J. Powell (Ph. D. dissertation) will greatly aid Genus: Campylodoniscus Kuhn, 1961 [nomen classification of the South American forms. dubium] The names of all of the new genera, as well as - Campylodan Bonaparte, 1978 [sic] of the new subfamilies, introduced in Powell's = Campylodon von Huene, 1929/Cuvier & dissertation have been published elsewhere Valenciennes, 1832 and are not new to this listing. C. ameghinoi (von Huene, 1929) (Type) = Campylodon ameghinoi von Huene, Genus: Aegyptosaurus Stromer, 1932 1929 [nomen dubium] A. baharijensis Stromer, 1932 (Type) Genus: Clasmodosaurus Ameghino, 1898 Genus: Aeolosaurus J. Powell, 1987 [nomen aubium] = Aelosaums BVP 1987 [sic] - Clasmodosaurus Rozhdestvensky & = Aeolosaurus J. Powell, 1986 [nomen Tatarinov, 1964 [sic] nudum] = Clasmodon von Huene, 1929 [sic] = Eolosaurus J. Powell vide Bonaparte, = Clasmosaurus Romer, 1966 [sic] 1985 [sic] C. spatula Ameghino, 1898 (Type)

Sauropodomorpha von Huene, 1932 1 Mesozoic Meanderings #2 = Clasmodon spatula (Ameghino, 1898) = Macrourosaurus Sauvage, 1879 [sic] [sic] M. semnus Seeley, 1876 (Type) NOTE: The above genus is probably a sau- Genus: von Huene, 1932 ropod and not a synonym of Genyodectes as fre­ [nomen dubium] quently classified (Molnar, 1980). It is listed as = Maggiarosaurus von Huene, 1956 [sic] a probable titanosaurid in J. Powell's disserta­ = Magiarosaurus Rozhdestvensky & tion (1986). Tatarinov, 1964 [sic] Genus: J. Powell, 1986 [nomen M. dacus (Nopcsa, 1915) [nomen dubium] nudum] = Titanosaurus dacus Nopcsa, 1915 = Epachtosaurus J. Powell, 1986 vide Mar­ [nomen dubium] tinez, Gim6nez, Rodriguez & Bochatey, M. transsylvanicus (von Huene, 1929) 1986 [nomen nudum] [nomen dubium] E. sciuttoi J. Powell, 1986 (Type) = Titanosaurus transsylvanicus von Huene, = Epachtosaurus sciuttoi J. Powell, 1986 1929 [nomen dubium] vide Martinez, Gimenez, Rodriguez & M. hungaricus von Huene, 1932 (Type) Bochatey, 1986 [nomen nudum] = Titanosaurus hungaricus (von Huene, NOTE: The above genus and species, de­ 1932) [nomen dubium] scribed in J. Powell's unpublished doctoral dis­ sertation, were published (and spelled slightly Genus: Microcoelus Lydekker, 1893 [nomen differently) without description in Martinez, Gi­ dubium; = ?] menez, Rodriguez '& Bochatey, 1986. = Microsaurops Kuhn, 1963 [sic] = Microsaurus Hatcher, 1900 vide Lull, Genus: Matheron, 1869 1910/Dejean, 1833 [sic] = Hypselaurus Villatte, Taquet & Bilotte, M. patagonicus Lydekker; 1893 (Type) 1985 [sic] NOTE: Synonymy of this genus with Salta- H. priscus Matheron, 1869 (Type) saurus is suggested by J. Mcintosh (pers. [New species from northern Spain; Bataller, comm.). 1960] Genus: Neuquensaurus J. Powell, 1986 vide Genus: Janenschia Wild, 1991 Bonaparte, 1987 [nomen nudum] /. robusta (E. Fraas, 1908) Wild, 1991 (Type) N. australis (Lydekker, 1893) (Type) = Gigantosaurus robustus E. Fraas, 1908 = Titanosaurus australis Lydekker, 1893 = Tomieria robusta (E. Fraas, 1908) N. robustus (von Huene, 1929) J. Powell, Sternfeld, 1911 1986 [nomen dubium] = Tomieria gigantea von Huene, 1956 [sic] = Titanosaurus robustus von Huene, 1929 NOTE: See note for Tomieria (Diplodoci- [nomen dubium] dae). = Saltasaurus robustus (von Huene, 1929) Mcintosh, 1990 [nomen dubium] Genus: Loricosaurus von Huene, 1929 [nomen NOTE: The name of the above genus was dubium; = Neuquensaurus'!] published without description in Bonaparte, L. scutatus von Huene, 1929 (Type) 1987, and its type species appeared in J. Pow­ NOTE: The above genus and species, based ell, 1987. The description of the genus, in Pow­ on dermal armor scutes, has previously been ell's doctoral dissertation, has not yet been pub­ classified as ankylosaurian. The scutes, howev­ lished. er, resemble those of the titanosaurid Saltasaur- us, and the species could well be a junior syno­ Genus: Saltasaurus Bonaparte & J. Powell, 1980 nym of Neuquensaurus australis (Bonaparte & 5. loricatus Bonaparte & J. Powell, 1980 J. Powell, 1980). (Type) Genus: Seeley, 1876 = Macrosaurus Thenius, 1972 [sic]

Parainf raclass Archosauria Cope, 1869 1 Sauropodomorpha von Huene, 1932 Genus: Titanosaurus Lydekker, 1877 large sauropod; Martinez, Gimenez, Rodri­ = Lametasaums Matley, 1923 [nomen guez & Luna, 1989] dubium; in part] Genus: [To be described from China; a possi­ = Lametasams Colbert, 1977 [sic] ble primitive titanosaurid; O. A. Russell, pers. = Laplatasaums von Huene, 1927 comm.] = Laplatosaums Obata & Kanie, 1977 [sic] = Tuamosaunis Colbert, 1952 [sic] = Titinosaurus Galton, 1981 [sic] T. indicus Lydekker, 1877 (Type) Family: CHUBUTISAURIDAE = Titanosaurus blanfordi Lydekker, 1879 del Corro, 1974 [nomen dubium] = Lametasaums indicus Matley, 1923 Census: 1 genus, 1 species [nomen dubium; in part] Genus: del Corro, 1974 T. nanus Lydekker, 1893 [nomen dubium] C. insignis del Corro, 1974 (Type) FT. madagascariensis Deperet, 1896 [nomen NOTE: This genus is probably a brachiosau- dubium] rid (Mcintosh, 1990). = Laplatasaums madagascariensis (Deper­ et, 1896) [nomen dubium] T. araukanicus (von Huene, 1929) J. Powell SAUROPODA incertae sedis 1986 = Laplatasaums araukanicus von Huene, Census: 1 doubtful genus, 1 doubtful species 1929 (Type) TT. fydekkeri von Huene, 1929 [nomen Genus: "Hisanohamasaunis" Lambert, 1990 [to dubium] be described from Japan] NOTE: The above species may belong to the genus Chondrosteosaurus (R. E. Molnar, Genus: Regnosaurus Mantell, 1848 [nomen pers. comm.). dubium] TT.faUod Hoffet, 1942 [nomen dubium] R. northamptoni Mantell, 1848 (Type) TT. rahioliensis Mathur & Srivastava, 1987 = northamptoni (Mantell, 1848) [nomen dubium] Genus: [To be described from Argentina by Calvo & J. F. Bonaparte] Genus: "Sugiyamasaurus" Lambert, 1990 [to be described from Japan; noted as having spatu- Genus: [To be described from North America; late teeth] Jensen, 1979] Genus: [To be described from Fergan, Soviet Genus: [To be described from procoelous cau­ Union; Rozhdestvensky, 1968] dal vertebrae from the of Argen­ tina; J. F. Bonaparte, pers. comm.; J. S. Genus: [To be described from the Toarcian Mcintosh, pers. comm.] (late Early Jurassic) of Morocco; Jenny, Jen- ny-Deshusses, la Marrec & Taquet, 1980] Genus: [To be described from the Cenomanian of Argentina; a huge sauropod with slender Genus: [To be described from the Toarcian limbs, very long pubis and ischium, and strap­ (late Early Jurassic) of Morocco (Jenny, Jen- like scapula; J. F. Bonaparte, pers. comm.; J. ny-Deshusses, la Marrec & Taquet, 1980] S. Mcintosh, pers. comm.] Genus: [To be described from China; based on Genus: [To be described from the Rio Limay a tooth; P. C. Sereno, pers. comm.] Formation of Neuquen, Argentina; a gigantic Genus: [To be described from the Oagannur titanosaurid; Bonaparte, 1989] Formation of Inner Mongolia; Dong Z., pers. Genus: [To be described from the Ma- comm.] tasiete Formation of Chubut, Argentina; a

Sauropodomorpha von Huene, 1932 1 Mesozoic Meanderings #2 Orden Segnosauria Barsbold & Perle, 1980 Census: 2 families, 5 genera, 6 species

Family: SEGNOSAURIDAE Perle, 1979 SEGNOSAURIA incertae sedis

Census: 3 genera, 3 species Census: 1 genus, 2 species = Enigmosauridae Barsbold, 1983 Genus: Nonshiungoscmrus Dong, 1979 = Nanshingosaurus Dong, 1980 [sic] Genus: Enigmosaums Barsbold & Perle, 1983 = Nanshungisaurus Paul, 1987 [sic] E. mongoliensis Barsbold & Perle, 1983 N. brevispinus Dong, 1979 (Type) (Type) Genus: [To be described] Genus: Eriikosaums Perle, 1980 [Type species to be redescribed] = Eriicosaums Perle, 1981 [sic] = Chilantaisaums zheziangensis Dong, 1979 E. andrewsi Perle, 1980 (Type) [Possible new species to be described from NOTE: This species is based on probable the of Alberta, segnosaunan pedal elements (Barsbold & Ma- Canada; P. J. Currie, pers. coram.] ryanska, 1990) and is thus not referable to the carnosaurian genus Chilantaisaums. Genus: Segnosaums Perle, 1979 Genus: [To be described; based on the large S. gaibinensis Perle, 1979 (Type) forelimb that was one of the two syntypes of = Segnosaums ghalbiensis Barsbold, 1983 Alectrosaums oiseni; MadCr & Bradley, 1989] [sic] Genus: [To be described from China; a primi­ tive form that according to D. A. Russell Family: THERIZ1NOSAURIDAE (pers. coram.) displays conclusive evidence Maleev, 1954 that segnosaurians are derived theropods and not sauropodomorphs; when this form is de­ Census: 1 genus, 1 species scribed, it my be necessary to remove the or­ der Segnosauria from the superorder Sauro- Genus: Therizinosaums Maleev, 1954 podomorpha and place it into the Theropodo- = Therezinosaurus Sukhanov, 1964 [sic] morpha] = Therisinosaurus Osmolska, 1980 [sic] T. cheloniformis Maleev, 1954 (Type)

Parainfraclass Archosauria Cope, 1869 147 Sauropodomorpha von Huene, 1932 Notes and New Taxa

Sauropodomorpha von Huene, 1932 148 Mesozoic Meanderings #2

t Superorden Ornithischia Seeley, 1888

Census: 6 orders, 19 families, 191 genera (42 doubtful), 280 species (83 doubtful)

Paraorden Lesothosauria nov. Census: 1 family, 6 genera (4 doubtful), 7 species (5 doubtful)

Family: LESOTHOSAURIDAE NOTE: Referred to as Ornithischia incertae L B. Halslead & J. Halstead, 1981 sedis in Sereno, 1991. Genus: Fabrosaums Ginsburg, 1964 [nomen Census: 1 genus, 1 species dubium in Weishampel & Witmer, 1990] = Eabrosaums Rozhdestvensky, 1974 [sic] Genus: Lesothosaums Galton, 1978 F. australis Ginsburg, 1964 (Type) L diagnosticus Gallon, 1978 (Type) = Fabrosaums australis Thulborn, 1970 Genus: Nanosaurus Marsh, 1877 [nomen non Ginsburg, 1964 dubium in Sues & Norman, 1990] = Nannosaurus Nopcsa, 1928 [sic] Genus: [To be described from the Sternberg M agilis Marsh, 1877 (Type) Series of ; a robust "fabrosau- NOTE: Sereno (1991) concludes that this rid"; P. M. Galton, pers. comm.; Crompton & genus and species represent an indeterminate Attridge, 1986] small ornithischian; referred to this family pro­ Genus: [To be described from the Upper Elliot visionally. Formation of South Africa; one or more gen­ Genus: Chatterjee, 1984 era may be present; A. P. Santa Luca, 1984; T. smalli Chatterjee, 1984 (Type) Gow, 1981,1985] NOTE: Sereno (1991) shows that the holo- type specimen is composite and includes both ornithischian and hatchling prosauropod ele­ LESOTHOSAURIA incertae sedis ments. Reference of this genus and species to this family here is provisional. Census: 5 genera (4 doubtful), 6 species (5 doubtful) Genus: Trimucrodon Thulborn, 1973 [nomen dubium in Weishampel & Witmer, 1990] = Fabrosauridae Galton, 1972 = Trimurodon Galton, 1980 [sic] = Nannosaurinae Nopcsa, 1928 [sic] T. cuneatus Thulborn, 1973 (Type) = Nanosauridae Marsh, 1878 NOTE: Referred to as Ornithischia incertae = Nanosaurinae Abel, 1919 sedis in Sereno, 1991. Genus: Alocodon Thulborn, 1973 [nomen dubi­ Genus: [To be described by P. E. Olsen and P. um in Weishampel & Witmer, 1990] M. Galton; P. M. Galton, pers. comm.] A. kuehnei Thulborn, 1973 (Type) [Type species to be redescribed]

Parainfraclass Archosauria Cope, 1869 149 Ornithischia Seeley, 1888 = Thecodontosaurus gibbidens Cope, 1878 Genus: [To be described from the Late Trias- [nomen dubium in Weishampel & Wit- sic of the Mendip Hills, ; Long & mer, 1990] Welles, 1975] Genus: [To be described from Nova Scotia; one or more genera may be present; P. E. Olsen, pers. comm.)

Paraorden Ankylosauria Osborn, 1923 Census: 3 families, 42 genera (12 doubtful), 51 species (18 doubtful) Genus: Colbert, 1981 Parafamily: SCEUDOSAURIDAE S. lawleri Colbert, 1981 (Type) Cope, 1869 NOTE: Previously classified as a "fabrosau- rid," the above genus is referred to the "Thyre- Census: 5 genera, 5 species ophora" by Gauthier (1986) and Sereno = Scelidosaurididae Nopcsa, 1917 [sic] (1986), but is provisionally referred to the Sce- = Scelidosaurinae Nopcsa, 1923 lidosauridae here. = Scuteilosauridae Lambert, 1990 Genus: Simmons, 1965 Genus: Emausaums Haubold, 1991 T. oehleri Simmons, 1965 (Type) E. emsti Haubold, 1991 (Type) NOTE: Simmons, in his description of the type specimen, noted its ankylosaurian affini­ Genus: Lusitanosaurus de Lapparent & Zby- ties but declined to refer the above genus to szewski, 1957 the Ankylosauria because the order was then L. liasicus de Lapparent & Zbyszewski, thought to be restricted to the Cretaceous. 1957 (Type) Now that ankylosaurian material is known from the Jurassic icf. various papers by Galton), this Genus: Scelidosaurus Owen, 1859 [nomen con- stricture no longer applies. Dong (1990), how­ servandum) ever, refers Tatisaurus to the Huayangosauri- = Scelodosaurus Gilmore, 1920 [sic] dae. S. hanisonii Owen, 1861 (Type) = Scelidosaurus hanisoni (Owen, 1861) Genus: [To be described from Great Britain; NOTE: Because no type specimen had been referred to by Rixon (1968) as a juvenile Sceli­ designated in the original description, Lydek- dosaurus but may be a new genus; Coombs, ker, 1893 made the lectotype specimen of Sceli­ Weishampel & Witmer, 1990] dosaurus hanisonii a megalosaurid knee joint that was part of the material originally referred to the species. This specimen will be rede- Family: NODOSAURIDAE Marsh, 1890 scribed in the forthcoming review of British theropod material by S. P. Welles and H. P. Census: 23 genera (9 doubtful), Powell as a new megalosaurid genus and spe­ 31 species (15 doubtful) cies, and the International Commission of Zoo­ logical Nomenclature will be petitioned to re­ = Acanthopholidae Nopcsa, 1917 [sic] tain the generic name Scelidosaurus for the ar­ = Acanthophoiididae Nopcsa, 1902 mored dinosaur under the nomen conservan- = Acanthopholidinae von Huene, 1956 dum rule. = Acanthopholinae Nopcsa, 1923 Padian (1989) has reported Scelidosaurus- = Edmontoniidae Bakker, 1988 like armor scutes from the = Edmontoniinae L S. Russell, 1940 of Arizona. = Hylaeosauridae Nopcsa, 1902

Ornithischia Seeley, 1888 150 Mesozoic Meanderings #2 = Hylaeosaurididae Nopcsa, 1917 [sic] Genus: Cryptodraco Lydekker, 1889 [nomen = Nodosaurinae Abel, 1919 dubium] = Palaeoscincidae Nopcsa, 1918 = Cryptosaurus Seeley, 1869/Geoffroy Saint- = Panoplosaurinae Nopcsa, 1929 Hilaire, 1833 = Panoplosaurines de Lapparent & = Crytodraco Delair, 1959 [sic] Lavocat, 1955 C. eumerus (Seeley, 1869) (Type) = Polacanthidae Wieland, 1911 = Cryptosaurus eumerus Seeley, 18699 = Polacanthines Lavocat, 1955 [nomen dubium] — Struthiosauridae Kuhn, 1966 Genus: Danubiosaurus Bunzel, 1871 [nomen = Struthiosaurinae Nopcsa, 1923 dubium] Genus: Huxley, 1867 [nomen = Danubriosaurus Romer, 1966 [sic] dubium] D. anceps Bunzel, 1871 (Type; in part) A. horridus Huxley, 1867 (Type) = Crataeomus pawlowitschii Seeley, 1881 A. eucercus Seeley, 1869 [nomen dubium] (in part) A. macrocercus Seeley, 1869 [nomen dubium] NOTE: The original type specimen of Danu­ ?A. platypus Seeley, 1869 [nomen dubium; biosaurus anceps is composite (K. Carpenter, sauropod?] pers. comm.). Most of the type material is ref­ = Macrurosaurus platypus (Seeley, 1869) erable to , but one scapula may [nomen dubium] represent a distinct genus. Until a restudy of A. stereocercus Seeley, 1869 [nomen dubium] the Gosau material is carried out, this scapula, once part of the type specimen of Crataeomus Genus: Brachypodosaums Chakravarti, 1934 pawlowitschii, is best separated from the other [nomen dubium] type material into the available genus Danubio­ = Brachyopodosaunts Gallon, 1981 [sic] saurus (Coombs, 1978; Molnar, 1980). K. Car­ B. gravis Chakravarti, 1934 (Type) penter (pers. comm.) further notes that Danubi­ NOTE: The above genus is referred to this osaurus is probably a nomen oblitum, and in a family provisionally (Coombs, 1978). It may be forthcoming article will designate lectotype spe­ a stegosaur (K. Carpenter, pers. comm.). cimens for some species of Struthiosaurus and Genus: Chasstembergia Bakker, 1988 [nomen Crataeomus. novum ex subgenera] Genus: Denversaurus Bakker, 1988 C. rugosidens (Gilmore, 1930) n. comb. D. schlessmani Bakker, 1988 (Type) (Type) NOTE: See also Chasstembergia and Edmon­ = rugosidens Gilmore, 1930 tonia. = Edmontonia rugosidens (Gilmore, 1930) = rugosidens (Gilmore, Genus: Dracopelta Gallon, 1980 1930) D. zbyszewskii Gallon, 1980 (Type) NOTE: Although Bakker (1988) introduced Chasstembergia as a subgenus of the genus Ed­ Paragenus: Edmontonia C. M. Sternberg, 1928 montonia, the name was never formally used as E. longiceps C. M. Sternberg, 1928 (Type) a subgenus (that is, in parenthesis following the = Panoplosaurus longiceps (C. M. generic name) in his paper. Further, it is clear Sternberg, 1928) from that paper's systematics discussion that if NOTE: This is a paragenus because it is al­ Denversaurus is to be removed from Edmonton­ most certainly ancestral to the genera Chas­ ia as a separate genus, so should Chasstember­ stembergia and Denversaurus; but see die note gia. This view is adopted here, although Car­ for Chasstembergia. penter (1990) and W. Coombs (pers. comm.) regard both Chasstembergia and Denversaurus as junior synonyms of Edmontonia.

Parainf raclass Archosauria Cope, 1869 151 Ornithischia Seeley, 1888 Genus: Hierosaurus Wieland, 1909 [nomen = Hylaeosaurus foxii (Hulke, 1881) dubium] = becklesi Hennig, 1924 - Heirosaums Colbert, 1961 [sic] [nomen dubium] - Xierosaurus Maleev, 1954 [sic] Genus: Priconodon Marsh, 1888 [nomen H. stembergii Wieland, 1909 (Type) dubium] = Nodosaurus stembergii (Wieland, 1909) - Princonodon Lull, 1911 [sic] Genus: Hopiitosaurus Lucas, 1902 ( = Polacan- P. crassus Marsh, 1888 (Type) thusl) = crassus (Marsh, 1888) = Xoplitosaums Maleev, 1954 [sic] [nomen dubium] H. marshi (Lucas, 1901) (Type) Genus: Priodontognathus Seeley, 1875 [nomen = Stegosaurus marshi Lucas, 1901 dubium] = Polacanthus marshi (Lucas, 1901) = Priodontosaurus Romer, 1966 [sic] Genus: Hylaeosaurus Mantell, 1833 P. phillipsii (Seeley, 1869) (Type) = Hyaelosaurus von Huene, 1909 [sic] = Iguanodon phillipsi Seeley, 1869 [nomen = Hylaeosaurus del Corro, 1974 [sic] dubium] = Hyleosaurus Maryanska, 1977 [sic] = phillipsi (Seeley, 1869) = Hylosaurus Fitzinger, 1843 [sic] [nomen dubium] H. armatus Mantell, 1833 (Type) = Omosaurus phillipsi (Seeley, 1869) = Hylaeosaurus mantelli Fitzinger, 1843 [nomen dubium] = Hylaeosaurus oweni Mantell, 1844 NOTE: The type specimen of this species is a nodosaurid left maxilla with teeth (Galton, Genus: Nodosaurus Marsh, 1889 1980); a femur referred to the species Omosau­ N. textilis Marsh, 1889 (Type) rus phillipsi by Seeley, 1893 is apparently stego- Genus: Palaeoscincus Leidy, 1856 [nomen saurian and should remain in the genus Dacen­ dubium] trurus (see Stegosauria). It is possible that Prio­ - Palaeosincus Maleev, 1956 [sic] dontognathus is a junior synonym of Hylaeosau­ = Palaeosynchus Stokes, 1988 [sic] rus or a. senior synonym of Cryptodroco (Gal­ P. costatus Leidy, 1856 (Type) ton, 1980), but it is unlikely to be differentiable P. lotus Marsh, 1892 [nomen dubium] from any described nodosaurid (K. Carpenter, P. magoder Hennig, 1914 [nomen nudum; pers. comm.). name created by typographical error: D. Genus: Sorcolestes Lydekker, 1893 Chure & J. S. Mcintosh, pers. comm.) S. leedsi Lydekker, 1893 (Type) Genus: Panoplosaurus Lambe, 1919 Genus: Souropelta Ostrom, 1970 = Panoplosaurus Galton, 1981 [sic] = Peltosaurus Glut, 1972/Cope, 1873 [sic] P. minis Lambe, 1919 (Type) S. edwardsorum Ostrom, 1970 (Type) Genus: Polacanthoides Nopcsa, 1928 =» Souropelta edwardsi Ostrom, 1970* P. ponderosus Nopcsa, 1928 (Type) NOTE: The specific name of the type spe­ NOTE: K. Carpenter (pers. comm.) will re- cies is emended to the genitive plural ending, describe the type scapula of the above species inasmuch as it is in honor of the entire Ed­ and establish it as a valid nodosaurid quite dis­ wards family. tinct from Hylaeosaurus and Polacanthus. Genus: Silvisaurus Eaton, 1960 Genus: Polacanthus Owen vide Huxley, 1867 S. condrayi Eaton, 1960 (Type) = Polacanthus Owen vide [Anonymous] Genus: Stegopelta Williston, 1905 (= Nodosau­ 1865 [nomen nudum] rus'}) =* Polecanthus McLoughlin, 1979 [sic] S. landerensis Williston, 1905 (Type) - Vectensia Delair, 1982 [nomen nudum] = Nodosaurus landerensis (Williston, 1905) P. foxii Hulke, 1881 (Type)

Ornithischia Seeley, 1888 152 Mesozoic Meanderings #2 Genus: Struthiosaums Bunzel, 1870 [nomen du­ NOTE: Coombs & Maryanska (1990) con­ bium] sider Stmthiosaums austriacus (and hence the = Crataeomus Seeley, 1881 [nomen dubium] genus Stmthiosaums), based on a single partial = Hoplosaurus Seeley, 1881 [nomen dubium] basicranium, to be a nomen dubium and possib­ = Leipsanosaurus Nopcsa, 1918 [nomen ly saurischian. They refer most of the Gosau dubium] nodosaurid taxa to an as-yet-unnamed new gen­ = Lepanosaums Romer, 1966 [sic] us (pending redescription of the Gosau mater­ = Plerropeltus Tumanova, 1987 [sic] ial) whose type species would be Stmthiosaums = Pleuropelas Coombs, 1971 [sic] transilvanicus. K. Carpenter (pers. comm.) fur­ = Pleuropeltus Seeley, 1881 [nomen dubium] ther notes that this genus is probably distin­ = Pluropeltus Rozhdestvensky & Tatarinov, guishable from Crataeomus. See also Danubio­ 1964 [sic] saurus. = Rhodanosaurus Nopcsa, 1929 [nomen ?S. ludgunensis (Nopcsa, 1929) [nomen dubium] dubium] S. austriacus Bunzel, 1871 (Type) = RJwdanosaums ludgunensis Nopcsa, = Danubiosaurus anceps Bunzel, 1871 1929 [nomen dubium] [nomen dubium; in part] = Stmthiosaums lugdunensis de Lapparent ?S. transilvanicus Nopcsa, 1915 & Lavocat, 1955 [sic] = Struthiosaums transylvanicus Nopcsa, = Stmthiosaums lugundensis Jeletsky, 1960 1915 [sic] [sic] = Struthiosaums transsylvanicus Nopcsa, Genus: [To be described by Carpenter, Dilkes 1929 [sic] & Weishampel] = Struthiosaums transilvaticus Coombs, [Type species to be redescribed] 1971 [sic] = Hierosaurus coleii Mehl, 1936 = Crataeomus Seeley, 1881 (no specific = Nodosaums coleii (Mehl, 1936) name assigned) = Crataeomus lepidophorus Seeley, 1881 Genus: [To be described from the Upper [nomen dubium] Cretaceous of Carlsbad, California; similar to = Struthiosaums lepidophorus (Seeley, Nodosaums] 1881) [nomen dubium] = Crataeomus pawlowitschii Seeley, 1881 [nomen dubium; in part] Family: ANKYLOSAURIDAE = Stmthiosaums pawlowitschii (Seeley, Brown, 1908 1881) [nomen dubium; in part] = Stmthiosaums pawlowitschi var. lepi­ Census: 14 genera (3 doubtful), dophorus (Seeley, 1881) Nopcsa, 1918 15 species (3 doubtful) [nomen dubium] = Hoplosaurus ischyrus Seeley, 1881 = Anchylosauridae Lydekker, 1909 [sic] [nomen dubium] = Ancylosauridae von Huene, 1908 [sic] = Nodosaums ischyrus (Seeley, 1881) = Ankylosaurinae Nopcsa, 1918 [nomen dubium] = Shamosaurinae Tumanova, 1983 = Pleuropeltus suessii Seeley, 1881 [nomen = Syrmosauridae Maleev, 1952 dubium] Genus: Brown, 1908 = Hoplosaurus insignis Sauvage, 1882 [sic] = Anchylosaurus C. H. Sternberg, 1917 [sic] = Leipsanosaurus noricus Nopcsa, 1918 = Ancylosaurus von Huene, 1909 [sic] [nomen dubium] A. magniventris Brown, 1908 (Type) = Stmthiosaums noricus (Nopcsa, 1918) = magniventris (Brown, [nomen dubium] 1908) = Crataeomus pavlowitschii Nopcsa, 1929 [sic] Genus: Dyoplosaums Parks, 1924

Parainfraclass Archosauria Cope, 1869 153 Omithischia Seeley, 1888 = Andontosaurus Bodily, 1969 [sic] Genus: Maleevus Tumanova, 1987 = Anodontosaums C. M. Sternberg, 1929 M. disparoserratus (Maleev, 1952) (Type) = Dioplosaums Hay, 1929 [sic] = Syrmosaurus disparoserratus Maleev, = Dyoplasaurus Maryanska, 1977 [sic] 1952 = Scalosaums Mehl, 1936 [sic] = Pinacosaurus disparoserratus (Maleev, = Scholosaums Minelli, 1987 [sic] 1952) = Scolasaurus Chevraux, 1980 [sic] = disparoserratus (Maleev, 1952) = Nopcsa, 1928 = Syrmosaurus disparoserrata Kuhn, 1964 = Skolosaums von Huene, 1954 [sic] [sic] D. acutosquameus Parks, 1924 (Type) = Talarurus disparsoserratus Maryanska, = Scolosaurus cutleri Nopcsa, 1928 1977 [sic] = Anodontosaums lambei C. M. Stern­ Genus: Minmi Molnar, 1980 berg, 1929 M. paravertebra Molnar, 1980 (Type) Paragenus: Euoplocephalus Lambe, 1910 NOTE: New material of this genus shows = Erroplocephalus Nopcsa, 1928 [sic] nodosaurid, ankylosaurid, and even stegosaurid = Euopiiocephaius [Anonymous] 1979 [sic] characters, probably indicating a more basal = Euoploasurus von Huene, 1956 [sic] position (Scelidosauridae or new family) for = Euoplocophalus Glut, 1972 [sic] this taxon (R. E. Molnar, pers. comm.). = Euoplology Hou, 1977 [sic] = Euoplosaurus Maleev, 1956 [sic] Genus: Peishansaums Bohlin, 1953 [nomen = Euplocephalus Lambe, 1920 [sic] dubium] = EuToplocephalus C. H. Sternberg, 1915 = Peishanosaurus Dong, 1979 [sic] P. philemys Bohlin, 1953 (Type) [sic] NOTE: The above genus is referred to this = Europocephaius Nopcsa, 1923 [sic] family provisionally. Coombs (1971) indicates = Sterecephalus Maleev, 1956 [sic] that the type specimen, a fragment from a very = Stereocephalus Lambe, 1902/Lynch Arri- small jaw, may not be a juvenile ankylosaurian baizaga, 1884 as originally classified; it may actually be a pa- = Sterocephalus Maleev, 1956 [sic] chycephalosaur (K. Carpenter, pers. comm.). E. tutus (Lambe, 1902) (Type) Bohlin's monograph also carries a plate cap­ = Stereocephalus tutus Lambe, 1902 tioned "Peishansaums latipons," but that is a = Palaeoscincus tutus (Lambe, 1902) typographical error for Peishanemys latipons, a = Palaeoscincus asper Lambe, 1902 chelonian. [nomen dubium] = Palaeoscincus rugosus Nopcsa, 1918 [sic] Genus: Pinacosaurus Gilmore, 1933 NOTE: The name Ankylosaurus acinaco- = Ninghsiasaums Young, 1965 [sic] dens, coined by Barnum Brown in the early - Syrmosaurus Maleev, 1952 1930s but never published, appears on file pho­ = Vuninicaudus von Huene, 1958 [sic] tographs of a Euoplocephalus specimen at the P. grangeri Gilmore, 1933 (Type) American Museum of Natural History. = Pinacosaurus ninghsiensis Young, 1935 This is a paragenus because it is almost cer­ = Syrmosaurus viminocaudus Maleev, 1952 tainly ancestral to the genera Dyoplosaurus and = Syrmosaurus viminicaudus Maleev, 1956 Ankylosaurus. [sic] - Pinacosaurus ninghsiaensis Young, 1964 Genus: Heishansaurus Bohlin, 1953 [nomen [sic] dubium] = Heischansaurus Rozhdestvensky, 1977 Genus: Maryanska, 1977 [sic] = Saichana Maryanska, 1977 [sic] = Heishanasaurus Glut, 1972 [sic] S. chulsanensis Maryanksa, 1977 (Type) = Heishanosaurus Swinton, 1970 [sic] H. pachycephalus Bohlin, 1953 (Type)

Ornithischia Seeley, 1888 154 Mesozoic Meanderinqs #2 Genus: Sangonghesaurus Zhao, 1983 [nomen Genus: Tenchisaurus [Anonymous] 1981 nudum] [nomen nudum; transliterated from Japanese] No type species named = Teinchisaurus Dong, 1987 [nomen nudum] No type species named Genus: Sauroplites Bohlin, 19S3 NOTE: The name of the above genus was S. scutiger Bohlin, 1953 (Type) published in Japanese in a dinosaur chart in = Sauroplites spiniger Maryanska, 1971 [sic] the guidebook to the Chinese dinosaur exhibi­ Genus: Shamosaurus Tumanova, 1983 tion in Japan in 1981; its spelling is a transliter­ = Shamosaurus Tumanova, 1981 [nomen ation provided by M. Tanimoto (pers. comm.). nudum] Dong Z. (pers. comm.) notes that a description S. scutatus Tumanova, 1983 (Type) of the genus is in preparation. Genus: Stegosaurides Bohlin, 19S3 [nomen Genus: [To be described from Maortu, China; dubium] may or may not be Tenchisaurus; Rozhdest- = Stegosauroides Colbert, 1961 [sic] vensky, 1961] S. excavatus Bohlin, 1953 (Type) Genus: [To be described from Shakh-Shakh, Genus: Talarurus Maleev, 1952 Mongolia; Rozhdestvensky, 1972] = Talararus Swinton, 1970 [sic] Genus: [To be described from the Lower Cre­ = Taiarusus Galton, 1970 [sic] taceous of Khovboor, Mongolia; a primitive T. plicatospineus Maleev, 1952 (Type) ankylosaurid; Kramarenko, 1974] Genus: Tarchia Maryanska, 1977 Genus: [To be described from the Late Creta­ T. gigantea (Maleev, 1956) ceous of Mongolia; a juvenile ankylosaurid = Dyoplosaurus giganteus Maleev, 1956 similar to but not congeneric with Pinacosau- = Euoplocephalus giganteus (Maleev, 1956) rus; P. Currie, pers. comm'.] T. kielanae Maryanska, 1977 (Type)

Order: Stegosauria Marsh, 1877 Census: 2 families, 14 genera (1 doubtful), 23 species (8 doubtful)

Parafamily: HUAYANGOSAURIDAE Family: STEGOSAURIDAE Marsh, 1877 Galton, 1990 Census: 13 genera (1 doubtful), Census: 1 genus, 1 species 22 species (8 doubtful)

= Huayangosaurinae Dong, Tang & = Hypsirhophidae Cope, 1898 Zhou, 1982 = Omosauridae Lydekker, 1888 = Huoyangosauridae Dodson & Dawson, = Stegosaurididae Nopcsa, 1917 [sic] 1991 [sic] = Stegosaurinae Abel, 1919 = Stegosauroidae Hay, 1930 Genus: Huayangosaurus Dong, Tang & Zhou, 1982 Genus: Changdusaums Zhao, 1986 [nomen = Huangosaurus Galton, 1986 [sic] nudum] H. taibaii Dong, Tang & Zhou, 1982 (Type) = Changtusaums Zhao, 1983 [nomen nudum] C. laminaplacodus Zhao, 1986 (Type)

Parainfraclass Archosauria Cope, 1869 155 Ornithischia Seeley, 1888 Genus: Chialingosaums Young, 1959 Genus: Dravidosaurus Yadagiri & Ayyasami, = Chialangosaurus Colbert, 1961 [sic] 1979 C. kuani Young, 1959 (Type) = Davidosaurus Gallon, 1981 [sic] D. blanfordi Yadagiri & Ayyasami, 1979 Genus: Chungkingosaums Dong, Zhou & (Type) Zhang, 1983 C. jiangbeiensis Dong, Zhou & Zhang, 1983 Genus: Hennig, 1915 (Type) = Centmrosaurus Nopcsa, 1917 [sic] = Doryphorosaurus Nopcsa, 1916 Genus: Craterosaurus Seeley, 1874 [nomen = Kentrurosaums Hennig, 1916 dubium] K. aethiopicus Hennig, 1915 (Type) C. pottonensis Seeley, 1874 (Type) = Doryphorosaurus aethiopicus (Hennig, Genus: Dacentrums Lucas, 1902 1915) = Dacentrosaums Dong, 1990 [sic] = Kentrurosaums aethiopicus (Hennig, = Dacentmrosaurus Hennig, 1925 [sic] 1915) = Omosaums Owen, 1875/Leidy, 1856 Genus: Hoffstetter, 1957 = Osmosaurus Gallon, 1980 [sic] = Lexousaurus Dong, Chang, Li & Zhou, D. armatus (Owen, 1875) (Type) 1978 [sic] = Omosaums armatus Owen, 1875 L. durobrivensis (Hulke, 1887) (Type) = Stegosaurus armatus (Owen, 1875) non = Omosaums durobrivensis Hulke, 1887 Marsh, 1877 = Stegosaurus durobrivensis (Hulke, 1887) = Omosaums lennieri Nopcsa, 1911 = Omosaums leedsi Seeley, 1901 vide von = Dacentrums lennieri (Nopcsa, 1911) Huene, 1901 [nomen dubium; in part] = Astrodon pusillus de Lapparent & Zby- = Lexovisaurus leedsi (Seeley, 1901) szewski, 1957 (juvenile) [nomen dubium] * = Pleurocoelus pusillus (de Lapparent & = Stegosaurus priscus Nopcsa, 1911 Zbyszewski, 1957) (juvenile) [nomen dubium; juvenile?] = Osmosaurus lennieri Gallon, 1980 [sic] = Lexovisaurus priscus (Nopcsa, 1911) D. hastiger (Owen, 1877) [nomen dubium] [nomen dubium; juvenile?] - Omosaums hastiger Owen, 1877 [nomen = Omosaums priscus (Nopcsa, 1911) dubium] [nomen dubium; juvenile?] ?D. phillipsi (Seeley, 1893) non (Seeley, ?L. vetustus (von Huene, 1910) [nomen 1869) [nomen dubium] dubium] =» Omosaums phillipsi Seeley, 1893 non = Omosaums vetustus von Huene, 1910 (Seeley, 1869) [nomen dubium] [nomen dubium] Genus: Diracodon Marsh, 1881 = Dacentrums vetustus (von Huene, 1910) = Diracondon Hay, 1901 [sic] [nomen dubium] D. laticeps Marsh, 1881 (Type) Genus: Monkonosaurus Zhao vide Dong, 1990 = Stegosaurus laticeps (Marsh, 1881) = Monkonosaurus Zhao, 1983 [nomen D. stenops (Marsh, 1887) Bakker, 1986 nudum] = Stegosaurus stenops Marsh, 1887 M. lawulacus Zhao vide Dong, 1990 (Type) NOTE: Synonymies within the above genus = Monkonosaurus lawulacus Zhao, 1986 are organized according to unpublished work [nomen nudum] by R. T. Bakker as reported at Boulder, Colo­ rado, 1986. See also Stegosaurus. = Monkonosaurus lawulocus Dong, 1987 [sic] Genus: Paranthodon Nopcsa, 1929 = Anthodon Owen, 1876 (in part) = Paracanthodon von Huene, 1956 [sic] P. africanus (Broom, 1910) (Type)

Ornithischia Seeley, 1888 156 Mesozoic Meanderings #2 = Palaeoscincus africanus Broom, 1910 1983 [sic] = Anthodon sen-anus Owen, 1876 (in part) = Tiejiangosaums Dong, Li, Zhou & = Paranthodon owenii Nopcsa, 1929 Zhang, 1977 [sic] = Tuajiangosaurus Dong, Zhou & Zhang, Genus: Stegosaums Marsh, 1877 1983 [sic] = Hypsirhophus Cope, 1878 [sic] = Tueojiangosaums Dong, Li, Zhou & = Hypsirophus Cope, 1878 [nomen dubium] Zhang, 1977 [sic] = Hypsirrhophus von Huene, 1909 [sic] = Tuojiangosaums [Anonymous] 1977 = Sregosaums Glut, 1972 [sic] [nomen nudum] = Stegosaums [Anonymous] 1980 [sic] = Tuojingosaums Gallon, 1981 [sic] S. armatus Marsh, 1877 (Type) = Tuojiongosaums Dong, Li, Zhou & S. discums (Cope, 1878) [nomen dubium] Zhang, 1977 [sic] = Hypsirophus discums Cope, 1878 T. muitispinus Dong, Li, Zhou & Zhang, [nomen dubium; type specimen probably composite] 1977 (Type) = Hypsirophus discursus Hennig, 1924 [sic] Genus: Wuerhosaums Dong, 1973 S. seeleyanus (Cope, 1879) [nomen dubium] = Wuherosaurus Sereno, 1986 [sic] = Hypsirhophus seeleyanus Cope, 1879 W. homheni Dong, 1973 (Type) [nomen dubium] Genus: Yingshanosaums Zhou, 1984 [nomen S. unguiatus Marsh, 1879 nudum] = Stegosaums duplex Marsh, 1887 No type species named = Stegosaums longispinus Gilmore, 1914 = Stegosaums altispinus Gilmore, 1914 [sic] Genus: [To be described from the Morrison S. affinis Marsh, 1881 [nomen dubium] Formation of Utah, presently referred to as S. sulcatus Marsh, 1887 [nomen dubium] the "Cleveland-Lloyd ankylosaur"; Madsen, [New species to be described from the Mor­ 1976] rison Formation of Colorado; R. T. Bak- ker, pers. comm.] Genus: [To be described from the Kota Forma­ NOTE: Synonymies within the above genus tion of India; Yadagiri, 1979] are organized according to unpublished work Genus: [To be described from the Maastrich- by R. T. Bakker as reported at Boulder, Colo­ tian of India; Yadagiri, 1979] rado, 1986. Listed as a paragenus because it is almost certainly ancestral to Diracodon. Genus: [To be described from the Ordos Basin of Inner Mongolia by Dong; similar to Wuer­ Genus: Tuojiangosaums Dong, Li, Zhou & hosaums but has only 12 dorsal vertebrae; col­ Zhang, 1977 lected in 1988; P. J. Currie, pers. comm.] = Taojiangosaurus Dong, Zhou & Zhang, Paraorden Pachycephalosauria Maryanska & Osmolska, 1974 Census: 4 families, 22 genera (1 doubtful), 24 species (4 doubtful)

Parafamily: PISANOSAURIDAE Parafamily: HETERODONTOSAURIDAE Casamiquela, 1967 Kuhn, 1966

Census: 1 genus, 1 species Census: 7 genera (1 doubtful), 7 species (3 doubtful) Genus: Pisanosaums Casamiquela, 1967 = Pisanosaum Dong, 1979 [sic] = Tianchungosauroidea Zhao, 1983 P. menu' Casamiquela, 1967 (Type) [nomen nudum]

Parainfraclass Archosauria Cope, 1869 157 Ornithischia Seeley, 1888 = Xiphosauridae Sereno, 1986 = angusticeps Gow, 1991 [sic] Genus: Hopson, 1975 Genus: Revueltosaums Hunt, 1989 [nomen A. consors (Thulbom, 1974) (Type) dubium] = Lycorhinus consors Thulbom, 1974 R. callenderi Hunt, 1989 (Type) NOTE: The above genus was described Genus: Dianchungosaums Young, 1982 [nomen from teeth that differ significantly in morpholo­ dubium] gy from those of other ornithischians but most = Diachungosaurus Haubold, 1990 [sic] closely resemble those of heterodontosaurids. = Tianchungosaurus Zhao, 1983 [sic] Referred to as Ornithischia indet. in Sereno, D. lufengensis Young, 1982 (Type) 1991; referred to this family provisionally. D. elegans Zhao, 1986 [nomen nudum] NOTE: It is possible that Dianchungosaums Genus: [To be described from the Morrison and Tianchungosaurus are distinct genera, with Formation of the Fruita, Colorado; a small or- D. elegans the type species of Tianchungosaur­ nithischian possibly referable to Echinodon; us, but without descriptions of Zhao's taxa this Callison & Quimby, 1984; P. M. Galton, pers. is presently indeterminable. Tianchungosaurus comra.] is supposed to represent a new family of pachy- cephalosaurians (Zhao, 1983), but to date no description of that genus — assuming it is dis­ Parafamily: CHAOYOUNGOSAURIDAE tinct from Young's genus — has been pub­ [nomen nudum; emendum ex lished. Chaoyoungosauroidea Zhao, 1983] Genus: Echinodon Owen, 1861 = Echinosaurus Morris, 1976 [sic] Census: Not taken = Sauraechinodon Falconer vide Owen, = Chaoyoungosauroidea Zhao, 1983 1861 [sic] [nomen nudum] = Sauraechmodon Falconer, 1861 = Saurechinodon Owen, 1861 [sic] Genus: Chaoyoungosaurus Zhao, 1983 [nomen E. becklesii Owen, 1861 (Type) nudum] = Echinodon becclesii Owen, 1861 [sic] = Chaoyangosaurus Dong, 1987 [sic] = Echinodon becklessii Galton, 1978 [sic] = Chaoyoungosaurus [Anonymous] 1981 NOTE: Referred to as a possible thyreopho- [nomen nudum; transliterated from Japa­ ran by Weishampel & Witmer (1990) and as a nese] possible heterodontosaurid by Sereno (1991). C. liaosiensis Zhao, 1983 (Type) Referred to this family provisionally. NOTE: The name of the above genus was first published in Japanese in a dinosaur chart Genus: Geranosaurus Broom, 1911 [nomen in the guidebook to the Chinese dinosaur exhi­ dubium] bition in Japan in 1981; its spelling is a transli­ G. atavus Broom, 1911 (Type) teration provided by M. Tanimoto (pers. Genus: Crompton & comm.). It is said to be described in Zhao's Charig, 1962 1983 monograph on Tibetan dinosaurs, but this H. tucki Crompton & Charig, 1962 (Type) work has thus far not been published. The fami­ = Lycorhinus tucki (Crompton & Charig, ly Chaoyoungosauridae is considered ancestral 1962) to the later pachycephalosaurs and the psittaco- saurs, but because there is no description, it is Genus: Lycorhinus Haughton, 1924 referred to the order Pachycephalosauria provi­ = Lanasaurus Gow, 1975 sionally. A description of Chaoyoungosaurus is = Lychorhinus Hopson, 1975 [sic] in preparation (Dong Z., pers. comm.). = Lycochinus Gallon, 1973 [sic] Zhao Xijin's name is now usually spelled L. angustidens Haughton, 1924 (Type) Chao Shichin. = Lanasaurus scalpridens Gow, 1975

Ornithischia Seeley, 1888 1 Mesozoic Meanderings #2 Genus: Xuanhuasaurus Zhao, 1986 [nomen Family: PACHYCEPHALOSAURIDAE nudum] C. M. Sternberg, 1945 X. niei Zhao, 1986 (Type) NOTE: Zhao (1986; partial translation by Xi Census: 9 genera, 11 species (1 doubtful) G. provided by R. E. Moinar) notes that the above genus, published without description, is = Domocephalinae Sereno, 1986 referable to the Chaoyoungosauridae. = Psalisauridae Larnbe, 1918 = Tholocephalidae Sereno, 1986 Parafamily: HOMALOCEPHAUDAE Genus: Gravitholus Wall & Galton, 1979 (Dong, 1978) Perle, Maryanska & G. albertae Wall & Galton, 1979 (Type) Osmblska, 1982 Genus: Majungatholus Sues & Taquet, 1979 = Majungotholus Goodwin, 1990 [sic] Census: 5 genera, 5 species M. atopus Sues & Taquet, 1979 (Type) = Stegosaurus madagascariensis Piveteau, = Homalocephaleridae Dong, 1978 1926 [nomen dubium] = Homalocephalosauridae Telles Antunes & Sigogneau-Russell, 1991 [sic] Genus: Omatotholus Galton & Sues, 1983 = Onatotholus Lucas, 1991 [sic] Genus: Perle, Maryanska & Os­ O. browni (Wall & Galton, 1979) (Type) mblska, 1982 = Stegoceras browni Wall & Galton, 1979 G. lattimorei Perle, Maryanska & Osmblska, 1982 (Type) Genus: Brown & Schlai- kjer, 1943 [nomen conservandum] Genus: Maryanska & Osmbl­ = Pachycephalosantus Sanz, 1990 [sic] ska, 1974 - Tylosteus Leidy, 1872 [nomen oblitum] = Homalocephale Dong, 1978 [sic] P. wyomingensis (Gilmore, 1931) (Type, as a = Homalecephale Carroll, 1987 [sic] senior synonym oiP. grangeri, the nominal - Homoalcephale Coombs, 1979 [sic] type of the genus) = Homocephale Paul, 1987 [sic] H. calathocercos Maryanska & Osm61ska, = Troodon wyomingensis Gilmore, 1931 1974 (Type) = Troodon wyomingensis Gilmore, 1931* = Stegoceras wyomingense (Gilmore, 1931) = Homalocephale calathoceras Morris, = Stegoceras wyomingensis (Gilmore, 1976 [sic] 1931)* Genus: Dong, 1978 = Tylosteus omatus Leidy, 1872 [nomen = Micropachycephale Dong, 1978 [sic] oblitum] M. hongtuyanensis Dong, 1978 (Type) = Pachycephalosaurus grangeri Brown & Schlaikjer, 1943 Genus: Taveirosaurus Telles Antunes & Sigog­ = Pachycephalosaurus reinheimeri Brown neau-Russell, 1991 & Schlaikjer, 1943 T. costai Telles Antunes & Sigogneau-Rus­ sell, 1991 (Type) Genus: Maryanska & Osmolska, 1974 Genus: Hou, 1977 P. prenes Maryanska & Osmblska, 1974 = Wannannosaums Dong, 1987 [sic] (Type) = Wannonosaurus Dong, 1978 [sic] W. yansiensis Hou, 1977 (Type) Genus: Stegoceras Lambe, 1902 = Stegoceros Galton, 1975 [sic] = Toodon Dong, 1979 [sic] - Troodon Gilmore, 1924 non Leidy, 1856 S. validum Lambe, 1902 (Type)

Parainf raclass Archosauria Cope, 1869 159 Omithischia Seeley, 1888 = Stegoceras validus Lambe, 1902* = Stenotholus kohlerorum Giffin, Gabriel = Troodon validus (Lambe, 1902) & Johnson, 1988 = Troodon validus (Lambe, 1902)* = Stenotholus kohleri Giffin, Gabriel & = Stegoceras breve Lambe, 1918 Johnson, 1988* = Stegoceras brevis Lambe, 1918* Genus: Maryanska & Osm61ska, = Troodon stembergi Brown & Schlaikjer, 1974 1943 ?T. bexelli (Bohlin, 1953) Olshevsky, 1978 = Troodon stembergi Brown & Schlaikjer, [nomen dubium] 1943* = Troodon bexelli Bohlin, 1953 [nomen = Stegoceras stembergi (Brown & Schlai­ dubium] kjer, 1943) = Troodon bexelli Bohlin, 1953 [nomen = Stegoceras iambei C. M. Sternberg, 1945 dubium]* S. edmontonense (Brown & Schlaikjer, 1943) - Stegoceras bexelli (Bohlin, 1953) [nomen = Stegoceras edmontonensis (Brown & dubium] Schlaikjer, 1943)* T. gilmorei Maryanska & Osm61ska, 1974 = Troodon edmontonensis Brown & (Type) Schlaikjer, 1943 = Troodon edmontonensis Brown & Genus: Galton, 1971 Schlaikjer, 1943* = Yarerlandia Dong, 1978 [sic] = Yavelandia Galton, 1975 [sic] Genus: Stygimoioch Gallon & Sues, 1983 = Yaverladia Dong, 1979 [sic] = Stenotholus Giffin, Gabriel & Johnson, Y. bitholus Galton, 1971 (Type) 1988 S. spinifer Galton & Sues, 1983 (Type) Genus: [To be described from northeastern Montana; a full-domed pachycephalosaur; Goodwin, 1990]

Order: Ceratopsia Marsh, 1890 Census: 3 families, 30 genera (4 doubtful), 56 species (9 doubtful) = osbomi Young, 1931 Parafamily: PSITTACOSAURIDAE = Psittacosaurus tingi Young, 1931 Osborn, 1923 == Psittacosaurus protiguanodonensis Young, 1958 Census: 1 genus, 5 species = Psittacosaurus guyangensis Cheng, 1982 = Protiguanodontinae Osbom, 1923 (juvenile) = Psittacosa urines Lavocat, 1955 P. sinensis Young, 1958 P. youngi Chao, 1963 Genus: Psittacosaurus Osborn, 1923 P. chaoyoungi Wang, 1983 [nomen nudum] = Prittacosaurus Rozhdestvensky, 1974 [sic] NOTE: This species has so far appeared on­ = Proiguanodon Dong, 1979 [sic] ly in faunal lists without description. It may = Protiguanodon Osborn, 1923 prove to be Chaoyoimgosaums (D. A. Russell, = Psittacorus Czerkas & Olson, 1987 [sic] pers. comm.). = Pssitacosaurus Santa Luca, 1980 [sic] P. xinjiangensis Sereno & Chao, 1988 P. mongoliensis Osborn, 1923 (Type) = Psittacosaurus xinjiangensis Dong, 1987 = Protiguanodon mongoliensis Osborn, [nomen nudum] 1923 P. meileyingensis Sereno, Chao, Cheng & = Protiguanodon mongoliense Osborn, Rao, 1988

Ornithischia Seeley, 1888 160 Mesozoic Meanderings #2 [New species to be described from the Low­ Genus: Microceratops Bohlin, 1953 er Cretaceous of the eastern USSR; speci­ M. gobiensis Bohlin, 1953 (Type) men discovered in the Moscow University Genus: C. M. Sternberg, 1951 collection but unlikely to be described in = Montanoceratops White, 1973 [sic] the near future; R. E. Molnar, pers. comm.] M. cerorhynchus (Brown & Schlaikjer, 1942) [Possible new species to be described from (Type) the Cretaceous of Thailand; cf. SVP Bul­ = Leptoceratops cerorhynchus Brown & letin #148, February, 1990: 57] Schlaikjer, 1942 NOTE: Synonymy within this genus is orga­ nized according to Sereno, 1990 Genus: Notoceratops Tapia, 1918 N. bonarellii Tapia, 1918 (Type) Genus: [To be described; a large, possibly aber­ = Notoceratops bonarelli Tapia, 1918* rant psittacosaurid with a skull approximately 70 cm. long, presently stored in a USSR muse­ Genus: Granger & Gregory, 1923 um; P. C. Sereno, pers. comm.] = Proceratops Dong, 1979/Lull, 1906 [sic] P. andrewsi Granger & Gregory, 1923 (Type) = Protoceratops andrewis [Anonymous] Parafamily: PROTOCERATOPSIDAE 1990 [sic] Granger & Gregory, 1923 Genus: von Meyer, 1857 = Stenopelyx Nopcsa, 1917 [sic] Census: 9 genera, 10 species S. valdensis von Meyer, 1857 (Type) = Asiaceratopsinae Nessov & NOTE: This genus may belong in the Chao- Kaznyshkina, 1989 youngosauridae. It is classified as a "basal mar- = Leptoceratopsinae Nopcsa, 1923 ginocephalian" by Dodson, 1990. = Protoceratopidae Steel, 1970 = Protoceratopsinae Nessov & Kaznyshkina, 1989 Family: CERATOPSIDAE Marsh, 1888 = Stenopeiixidae Kuhn, 1966 = Stenopelyxidae Nopcsa, 1917 Census: 2 subfamilies, 16 genera (2 doubtful), 34 species (4 doubtful) Genus: Asiaceratops Nessov & Kaznyshkina, 1989 = Ceratopidae Lydekker, 1889 A. sukidens (Bohlin, 1953) = Ceratopsoidae Hay, 1930 = Microceratops sukidens Bohlin, 1953 A. salsopaludalis Nessov & Kaznyshkina, Parasubfamily: Eucentrosaurinae 1989 (Type) [nomen novum ex Centrosaurinae Lambe, 1915] Genus: Bagaceratops Maryanska & Osm61ska, 1975 Census: 6 genera, 16 species (1 doubtful) B. rozhdestvenskyi Maryanska & Osmolska, 1975 (Type) = Monocloniinae Nopcsa, 1928 Genus: Breviceratops Kurzanov, 1990 = Monocloninae Nopcsa, 1923 B. kozlowskii (Maryanska & Osmdlska, = Pachyrhinosauridae 1975) Kurzanov, 1990 (Type) C. M. Sternberg, 1950 = Protoceratops kozlowskii Maryanska & Genus: Avaceratops Dodson, 1986 Osm61ska, 1975 = Azaceratops Stokes, 1988 [sic] Genus: Leptoceratops Brown, 1914 A. lammersorum Dodson, 1986 (Type) = Leptoceratops Osm61ska, 1986 [sic] = Avaceratops lammersi Dodson, 1986* L. gracilis Brown, 1914 (Type)

Parainfraclass Archosauria Cope, 1869 161 Ornithischia Seeley, 1888 NOTE: The specific name of the type spe­ (1989) should be used for this genus. This is cies is emended to the genitive plural ending, also reflected in the name change of this para- inasmuch as it honors the entire Lammers fami- subfamily to Eucentrosaurinae from Centrosau- iy- rinae. Genus: Gilmore, 1914 Genus: Monoclonius Cope, 1876 B. montanensis Gilmore, 1914 (Type) = Monoclonins Kuhn, 1964 [sic] = Monoclonius montanensis (Gilmore, M. crassus Cope, 1876 (Type) 1914) = Monoclonius sphenocems Cope, 1889 [nomen dubium] Genus: Eucentrosaums Chure & Mcintosh, - sphenocems (Cope, 1889) 1989 [nomen dubium] = Centrosaums Lambe, 1904/Fitzinger, 1843 M. fissus Cope, 1889 = Centrosaums L. S. Russell, 1966 [sic] M. dawsoni Lambe, 1902 ?E. recurvicomis (Cope, 1889) [nomen = Brachyceratops dawsoni (Lambe, 1902) dubium] Parks, 1925 = Monoclonius recurvicomis Cope, 1889 M. lowei C. M. Sternberg, 1940 [nomen dubium] NOTE: Work on ceratopsid bone beds in = Centrosaums recurvicomis (Cope, 1889) Alberta, Canada by S. Sampson and D. Tanke, [nomen dubium] reported at the 1990 SVP annual meeting, indi­ = Centrosaums recurvatus Langston, 1975 cates that much if not all material referred to [sic] the genus Monoclonius represents juvenile, sub- E. apertus (Lambe, 1904) (Type) adult, or sexually immature individuals of other = Centrosaums apertus Lambe, 1904 centrosaurine ceratopsids. = Monoclonius apertus (Lambe, 1904) E.flexus (Brown, 1914) Genus: Pachyrhinosaums C. M. Sternberg, 1950 = Centrosaums flexus Brown, 1914 P. canadensis C. M. Sternberg, 1950 (Type) = Monoclonius flexus (Brown, 1914) [New species to be described from the Ju­ = Monoclonius inflexus Kuhn, 1936 [sic] dith River Formation of Alberta, Canada E. nasicomus (Brown, 1917) by W. Langston, P. J. Currie, and D. = Monoclonius nasicomus Brown, 1917 Tanke] = Centrosaums nasicomus (Brown, 1917) E. cutleri (Brown, 1917) Genus: Styracosaurus Lambe, 1913 (= Eucen­ = Monoclonius cutleri Brown, 1917 trosaums or Monoclonius?) = Centrosaums cutleri (Brown, 1917) = Stylacosaums Charig & Horsfield, 1975 E. longirostris (C. M. Sternberg, 1940) [sic] = Centrosaums longirostris C. M. Stern­ S. albertensis Lambe, 1913 (Type) berg, 1940 = Monoclonius albertensis (Lambe, 1913) S. ovatus Gilmore, 1930 = Monoclonius longirostris (C. M. Stern­ S. parksi Brown & Schlaikjer, 1937 berg, 1940) NOTE: The name Styracosaurus borealis, NOTE: If Styracosaurus is found to be a syn­ coined by Barnum Brown in the 1930s but nev­ onym of the genus Centrosaums (Dodson, er published, appears on Hie photographs of 1990), then renaming the genus Eucentrosaums the type specimen of the above species at the would be superfluous; Styracosaurus would sim­ American Museum of Natural History. Also ply replace the preoccupied Centrosaums. Al­ see note for Eucentrosaums above. so, it is possible that Centrosaums Fitzinger, 1843 is a nomen oblitum under the "50-year S. makeli Czerkas & Czerkas, 1990 [nomen rule," in which case Centrosaums Lambe, 1904 nudum] would not be preoccupied after all. Until these NOTE: The above species name appears questions are satisfactorily resolved, however, without formal description in a picture caption the new name suggested in Chure & Mcintosh for an as-yet-undescribed species of Styracosau-

Ornithischia Seeley, 1888 162 Mesozoic Meanderings #2 rus from the of Mon­ NOTE: Listed as a paragenus because it is tana. It is characterized by a single long epoc- almost certainly ancestral to the genus Pentacer- cipital horn on each parietal and a nasal horn atops. that overhangs the beak. The name may be Genus: Ceratops Marsh, 1888/Rafinesque, 1815 spelled differently when the species is formally [nomen dubium] described. = Proceratops LulL 1906 C montanus Marsh, 1888 (Type) = Proceratops montanus (Marsh, 1888) Subfamily: Chasmosaurinae = montanus (Marsh, 1888) Lambe, 1915 [sic; a typographical error in Ostrom & Wellnhofer, 1986; J. H. Ostrom, pers. Census: 10 genera (2 doubtful), comm.] 18 species (3 doubtful) NOTE: Substitution of Proceratops for Cera­ tops by Lull, 1906 was unnecessary, as Ceratops = Ceratopsinae Abel, 1919 Rafinesque, 1815 was by then a nomen oblitum = Eoceratopsinae Lambe, 1915 (R. E. Molnar, pers. comm.). Genus: Anchiceratops Brown, 1914 A. omatus Brown, 1914 (Type) Genus: Diceratops Hatcher vide LulL 1905 A. longirostris C. M. Sternberg, 1929 D. hatched Lull, 1907 (Type) = Triceratops hatcheri (Lull, 1907) Paragenus: Arrhinoceratops Parks, 1925 NOTE: Recent work on the systematics of A. brachyops Parks, 1925 (Type) the genus Triceratops by Catherine Forster (pre­ NOTE: Listed as a paragenus because it is sented at the 1990 SVP annual meeting) indi­ almost certainly ancestral to the genus Torosau- cates that Diceratops is-distinct from Tricera­ ms. tops rather than a junior synonym as usually classified. Paragenus: Lambe, 1914 (= Ceratops?) Genus: Eoceratops Lambe, 1915 (= juvenile = Chasamosaurus C. H. Sternberg, 1932 Chasmosaurus or Ceratops?) [sic] E. canadensis (Lambe, 1902) (Type) = Chasmatosaums Maryanska & Osm6lska, - Monoclonius canadensis Lambe 1902 1979/Haughton, 1924 [sic] = Ceratops canadensis (Lambe, 1902) = Protorosaunis Lambe, 1914/von Meyer, 1830 Genus: Osborn, 1923 C. belli (Lambe, 1902) (Type) P. stembergii Osborn, 1923 (Type) = Monoclonius belli Lambe, 1902 = Chasmosaurus stembergii (Osborn, 1923) = Protorosaunis belli (Lambe, 1902) P. fenestratus Wiman, 1930 = Chasamosaurus ceratops C. H. Stern­ Genus: Marsh, 1891 berg, 1932 [sic] T. latus Marsh, 1891 (Type) = Chasmosaurus brevirostris Lull, 1933 = Torosaurus gladius Marsh, 1891 (juvenile) T. utahensis (Gilmore, 1946) Lawson, 1976 ?C. kaiseni Brown, 1933 = Arrhinoceratops utahensis Gilmore, 1946 NOTE: The above species may represent a new ceratopsid genus, though it may also be a Genus: Triceratops Marsh, 1889 "male" Chasmosaurus belli if sexual dimor­ = Claorhynchus Cope, 1892 [nomen dubium] phism can be proved within the genus. = Pofyonax Cope, 1874 [nomen dubium] C. russelli C. M. Sternberg, 1940 = Sterrholophus Marsh, 1891 C. mariscalensis Lehman, 1989 = Tirceratops Parks, 1925 [sic] = Tricerotops Stokes, 1988 [sic] ?T. alticomis (Marsh, 1887) [nomen dubium]

Parainfraclass Archosauria Cope, 1869 1 Ornithischia Seeley, 1888 = Bison alticomis Marsh, 1887 [nomen Genus: Ugrosaurus Cobabe & Fastovsky, 1987 dubium] [nomen dubium; = Triceratops!] = Ceratops alticomis (Marsh, 1887) U. olsoni Cobabe & Fastovsky, 1987 (Type) [nomen dubium] T. honidus (Marsh, 1889) (Type) = Ceratops honidus Marsh, 1889 Ceratopsidae incertae sedis = Pofyonax mortuarius Cope, 1874 [nomen dubium; juvenile] Census: 4 genera (2 doubtful), = Agathaumas mortuarius (Cope, 1874) 7 species (5 doubtful) [nomen dubium; juvenile] =» Triceratops mortuarius (Cope, 1874) = Agathaumidae Cope, 1889 [nomen dubium; juvenile] Genus: Agathaumas Cope, 1872 [nomen = Triceratops flabellatusMarsh , 1889 dubium; — Brachyceratops?] = Sterrholophus flabellatus (Marsh, 1889) = Agathaumus Baur, 1891 vide Hay, 1901 Marsh, 1891 [sic] = Triceratops galeus Marsh, 1889 [nomen A. sylvestris Cope, 1872 (Type) dubium] = Triceratops sylvestris (Cope, 1872) = Triceratops sulcatus Marsh, 1890 [nomen dubium] [nomen dubium] - Triceratops prorsus Marsh, 1890 Genus: Arstanosaurus Suslov vide Suslov & = Triceratops serratus Marsh, 1890 Shilin, 1982 = Triceratops elatus Marsh, 1891 A. akkurganensis Suslov & Shilin, 1982 = Claorhynchus trihedrus Cope, 1892 (Type) [nomen dubium] NOTE: The type specimen of this species is = Triceratops obtusus Marsh, 1898 a maxilla referable to,the Ceratopsidae (D. B. = Triceratops calicomis Marsh, 1898 Weishampel, pers. comm.; Nessov & Kaznysh­ = Triceratops califomis Wolcott, 1900 [sic] kina, 1989). = Triceratops brevicomus Hatcher, 1905 Genus: Dysganus Cope, 1876 [nomen dubium] (juvenile) D. encaustus Cope, 1876 (Type) = Triceratops ingens Lull, 1915 [nomen D. bicarinatus Cope, 1876 [nomen dubium] nudum] D. haydenianus Cope, 1876 [nomen dubium] = Triceratops maximus Brown, 1933 D. peiganus Cope, 1876 [nomen dubium] [nomen dubium] NOTE: Coombs & Galton (1988) review the - Triceratops albertensis C. M. Sternberg, material (teeth) assigned to the species in this 1949 genus and conclude that although it is all cera- = Triceratops brevirostris Sloan, 1976 [sic] topsid, it cannot be defined below the family TT. eurycephalus Schlaikjer, 1935 level. The genus and all included species are NOTE: Recent work on the systematica of considered nomina dubia. Triceratops by Catherine Forster, reported at the 1990 SVP annual meeting, indicates that Genus: Turanoceratops Nessov & Kaznyshkina, the above species of Triceratops is distinct from 1989 7*. honidus and may even belong in a different T. tardabilis Nessov & Kaznyshkina, 1989 genus. All the other species of Triceratops ex­ (Type) cept T. alticomus remain junior synonyms of T. honidus, as shown in Ostrom & Wellnhofer, 1986.

Ornithischia Seeley, 1888 164 Mesozoic Meanderings #2 Superorder: Ornithischia Seeley, 1888 (continued)

Order: Ornithopoda Marsh, 1871 Census: 6 families, 74 genera (17 doubtful), 115 species (35 doubtful) = Gongbusaums shiyi Dong, 1987 [sic] Parafamily: HYPSILOPHODONTIDAE G. wucaiwanensis Dong, 1989 DollO, 1882 = Gongbusaums wucaiwanensis Dong, 1986 [nomen nudum] Census: 17 genera (4 doubtful), 25 species (5 doubtful) Genus: Hypsilophodon Huxley, 1869 H. faxii Huxley, 1869 (Type) = Hypsilophodontinae Abel, 1919 = Hypsilophodon fori (Huxley, 1869) = Laosauridae Marsh, 1879 =» Iguanodon fan (Huxley, 1869) [nomen oblitum] = Camptosaums valdensis Lydekker, 1889 = Laosaurinae Abel, 1919 [nomen dubium in Sues & Norman, 1990] = Thescelosauridae C. M. Sternberg, 1937 H. wielandi Galton & Jensen, 1979 (not 1978) [nomen dubium in Sues & Norman, Genus: Atlascopcosaums T. Rich & P. Rich, 1990] 1989 = Atlascoplosaums Haubold, 1990 [sic] Genus: Laosaums Marsh, 1878 [nomen dubium] A. loadsi T. Rich & P. Rich, 1989 (Type) L. celer Marsh, 1878 (Type) Genus: Drinker Bakker, Gallon, Siegwarth & Genus: T. Rich & P. Rich, 1989 Fdla,1990 = Leaellynasaums Haubold, 1990 [sic] D. nisti Bakker, Galton, Siegwarth & Filla, L amicagraphica T. Rich & P. Rich, 1989 1990 (Type) (Type) NOTE: The above genus, along with Othniel- ia, is excluded from the Hypsilophodontidae in Genus: Othnielia Galton, 1977 the original description. Referred to this family = Othneilia Galton & H. P. Powell, 1980 provisionally. [sic] O. rex (Marsh, 1877) (Type) Genus: Fuigurotherium von Huene, 1932 = Nanosaurus rex Marsh, 1877 [nomen dubium] = Laosaums rex (Marsh, 1877) F. australe von Huene, 1932 (Type) = Laosaums gracilis Marsh, 1878 Genus: Gongbusaums Dong, Zhou & Zhang, O. consors (Marsh, 1894; = O. rex?) 1983 = Laosaums consors Marsh, 1894 = Gubisaurus Dong, Zhou & Zhang, 1983 NOTE: The above genus, along with Drink­ [sic] er, is excluded from the Hypsilophodontidae by G. shiyii Dong, Zhou & Zhang, 1983 (Type)

Parainfraclass Archosauria Cope, 1869 165 Ornithischia Seeley, 1888 Bakker, Gallon, Siegwarth & Filla, 1990. Re­ — suessi var. robustus Nopcsa, ferred to this family provisionally. 1901 [nomen dubium] — Mochlodon suessi var. robustum Genus: Horner & Weishampel, Nopcsa, 1901 [nomen dubium]* 1988 — Onychosaums hungaricus Nopcsa, 1902 O. makelai Horner & Weishampel, 1988 [nomen dubium] (Type) R. septimanicus Buffetaut & Le Loeuff, 1991 Genus: Parksosaums C. M. Sternberg, 1937 NOTE: ICZN Opinion #1483 suppresses = Parkosaums Czerkas & Olson, 1987 [sic] the earlier genus Fleischmann, P. warreni (Parks, 1926) (Type) 1831 as a nomen oblitum and conserves Rhab­ = Thescelosaums warreni Parks, 1926 dodon Matheron, 1869 for the unpreoccupied NOTE: The above genus is referred to this name of this genus. The same publication also family provisionally. corrects the spelling of the type-specific name to Rhabdodon priscus. Genus: Thulborn, 1973 [nomen dubium in Sues & Norman, 1990] Genus: Tenontosaurus Ostrom, 1970 P. henkeli Thulborn, 1973 (Type) = Tenantosaums Brown vide Chure & Mcintosh, 1989 Genus: Rhabdodon Matheron, 1869 [nomen T. tillettomm Ostrom, 1970 (Type) conservandum] = Tenontosaurus tilletti Ostrom, 1970* = Machlodon Glut, 1972 [sic] = Tenantosaums kaiseni Brown vide = Mochlodon Seeley, 1881 Chure & Mcintosh, 1989 = Oligosaums Seeley, 1881 [nomen dubium] NOTE: The specific name of the type spe­ - Onychosaums Nopcsa, 1902 [nomen cies is here emended to the genitive plural end­ dubium] ing, inasmuch as it is in honor of the entire Til- = Omithomems Seeley, 1881 [nomen lett family (see Ostrom, 1970). The names Eure- dubium] odon kaiseni and Tenantosaums kaiseni, coined = Rabdodon Matheron, 1869 [sic] in the 1930s by Barnum Brown but never = Rhabodon Kuhn, 1964 [sic] published, appear on American Museum of R. priscus Matheron, 1869 (Type) Natural History file photographs of the "camp- = Rhabdodon priscum Matheron, 1869* tosaurid" specimen (AMNH 3034) that is re­ = Rabdodon priscum Matheron, 1869 [sic] ferred to Tenontosaurus in Ostrom, 1970. = Iguanodon suessi Bunzel, 1871 [New species to be described from the Com- = Mochlodon suessi (Bunzel, 1871) = Rhabdodon suessi (Bunzel, 1871) anchean of Texas; Langston, 1974] = Oligosaums adelus Seeley, 1881 [nomen [New species to be described from Doss dubium] Ranch, Texas; may represent a new genus; discussed at the 1989 SVP Annual Meet­ = Omithomems gracilis Seeley, 1881 ing] [nomen dubium; juvenile?] NOTE: This genus is classified outside the = Camptosaurus inkeyi Nopcsa, 1899 Hypsilophodontidae, Dryosauridae, and Camp- = Mochlodon inkeyi (Nopcsa, 1899) tosauridae by Sues & Norman (1990) and on = Rhabdodon inkeyi (Nopcsa, 1899) further study will probably require its own fam­ =» Mochlodon robustus Nopcsa, 1900 ily. Referred to the Hypsilophodontidae provi­ [nomen dubium] sionally. - Mochlodon robustum Nopcsa, 1900 [nomen dubium]* Genus: Thescelosaums Gilmore, 1913 = Rhabdodon robustus (Nopcsa, 1900) Z neglectus Gilmore, 1913 (Type) [nomen dubium] 7T. edmontonensis Sternberg, 1940 = Rhabdodon robustum (Nopcsa, 1900) TT. garbanii Morris, 1976 [nomen dubium]*

Ornithischia Seeley, 1888 166 Mesozoic Meanderings #2 Genus: Xiaosaurus Dong & Tang, 1983 [nomen Genus: [To be described from James Ross Is­ dubium in Weishampel & Witmer, 1990] land, British ; based on partial = Xiaosaurus Dong, 1983 [nomen nudum] skull, anterior vertebral column, pectoral gir­ X. dashanpensis Dong & Tang, 1983 (Type) dle, and pelvis of an animal about 5 meters = Xiaosaurus dashanpenensis Dong, 1983 long] [nomen nudum] NOTE: Some references list this species as a synonym of Yandusaurus multidens, but Sere- Family: DRYOSAURIDAE no (1991) considers it a nomen dubium and Milner & Norman, 1984 classifies the genus as Ornithischia incertae se- dis. Census: 3 genera (1 doubtful), 5 species (1 doubtful) Genus: Yandusaurus He, 1979 = Honghesaurus [Anonymous] 1981 [sic] = Dryosaurinae Cooper, 1985 = Hunhosaurus Dong, Zhou & Zhang, 1983 [sic] Genus: Dryosaurus Marsh, 1894 = Yubasaurus He, 1975? [sic] = Drysaurus Galton, 1977 [sic] Y. hongheensis He, 1979 (Type) - Dypsalotosaurus Galton, 1973 [sic] Y. multidens He & Cai, 1983 = Dysalatosaurus Colbert, 1961 [sic] NOTE: The reference to Yubasaurus has not - Dysaiotasaurus Ostrom, 1970 [sic] yet been seen. If the date given above is cor­ = Dysaiotasaurus Virchow, 1919 rect, the name may have priority over Yan­ D. alius (Marsh, 1878) (Type) dusaurus. = Laosaurus alius Marsh, 1878 D. lettowvorbecki (Virchow, 1919) Genus: Zephyrosaurus Sues, 1980 = Dysaiotasaurus lettowvorbecki Virchow, Z. schaffi Sues, 1980 (Type) 1919 Genus: [To be described; may be Orodromeus = Dysaiotasaurus lettow-vorbecki Virchow, or a new genus; J. R. Horner, pers. comm.] 1919* [Type species to be redescribed] Genus: Haughton, 1915 [nomen = Laosaurus minimus Gilmore, 1924 dubium in Sues & Norman, 1990] = Othnielia minima (Gilmore, 1924) K. coetzeei Haughton, 1915 (Type) Genus: [To be described from the Newark For­ Genus: Galton, 1977 mation; Olsen & Gallon, 1977] V. canaliculars (Galton, 1975) (Type) Genus: [To be described from the Newark For­ = Dryosaurus canaliculars Galton, 1975 mation; Olsen & Galton, 1977] V. nigeriensis Galton & Taquet, 1982 Genus: [To be described from the Newark For­ mation; Olsen & Galton, 1977] Family: CAMPTOSAURIDAE Genus: [To be described from the Hell Creek Marsh, 1885 Formation; referred to as sp. in Morris, 1976; Sues, 1980] Census: 3 genera, 5 species Genus: [To be described from the Morrison = Camptonotidae Marsh, 1881 Formation; based on remains originally re­ = Camptosaurinae Abel, 1919 ferred to Nanosaurus agilis; P. M. Galton, pers. comm.] Genus: Callovosaurus Galton, 1980 C. leedsi (Lydekker, 1889) (Type) Genus: [To be described from Proctor Lake, = Camptasaums leedsi Lydekker, 1889 Texas; Winkler, Jacobs, et ai, 1988]

Parainf raclass Archosauria Cope, 1869 167 Ornithischia Seeley, 1888 Genus: Camptosaurus Marsh, 1885 Parafamily: IGUANODONTIOAE = Brachyrophus Cope, 1878 [nomen dubium] Cope, 1869 = Brachyrhophus Kuhn, 1965 [sic] = Campotonodus Romer, 1966 [sic] = Camptonodus Hoffmann, 1880 [sic] Census: 7 genera (3 doubtful), = Camptonotus Marsh, 1879/Uhler, 1864 21 species (9 doubtful) = Camptonutus Gallon & Jensen, 1979 (not = Iguanodontinae Abel, 1919 1978) [sic] = Iguanodontoidae Hay, 1930 = Cumnoria Seeley, 1888 = Iguanodontoides Gervais, 1853 = Cumnovia Cams, 1888 [sic] = Iguanodotidae Delair, 1959 [sic] = Cunmoria Nopcsa, 1917 [sic] = Kalodontidae Nopcsa, 1901 - Symphyrophus Cope, 1878 [nomen dubium] Genus: Anopiosaurus Seeley, 1878 [nomen = Symphyrosaurus von Huene, 1908 [sic] dubium] C. dispar (Marsh, 1879) (Type) = Anoplocephalus Hennig, 1924 [sic] = Camptonotus dispar Marsh, 1879 = Eucercosaurus Seeley, 1879 [nomen = Cumnoria dispar (Marsh, 1879) dubium] = Brachyrophus altarkansanus Cope, 1878 = Eucerosaurus Romer, 1966 [sic] [nomen dubium] = Sygmosaurus Sauvage, 1878 [sic] - Symphyrophus musculosus Cope, 1878 = Syngonosaums Seeley, 1878 [nomen [nomen dubium] dubium] = Camptosaurus medius Marsh, 1894 A. macrocercus (Seeley, 1869) [nomen = Camptosaurus nanus Marsh, 1894 dubium] = Camptosaurus browni Gilmore, 1909 = Acanthopholis macrocercus Seeley, 1869 C prestwichii (Hulke, 1880) [nomen dubium;in part] = Iguanodon prestwichii Hulke, 1880 = Syngonosaums macrocercus (Seeley, = Cumnoria prestwichi (Hulke, 1880) 1869) [nomen dubium] ?C. depressus Gilmore, 1909 = Syngonosaums macrourus Hennig, 1924 [sic] Genus: Bartholomai & Mol­ — Anopiosaurus macromerus Kuhn, 1936 nar, 1981 [sic] M. langdoni Bartholomai & Molnar, 1981 A. curtonotus Seeley, 1878 (Type) (Type) = Anopiosaurus curtonodus Coombs, 1971 NOTE: Generally classified as an iguano- [sic] dontid, this genus may actually be a large camp- A. major Seeley, 1878 [nomen dubium] tosaurid (R. E. Molnar, pers. comm.). Re­ = Acanthopholis stereocercus Seeley, 1869 ferred to this family provisionally. [nomen dubium; in part] Genus: [To be described from the Lower Cre­ A. tanyspondylus (Seeley, 1878) [nomen taceous of North America; bears a cranial dubium] crest] = Eucercosaurus tanyspondylus Seeley, 1878 [nomen dubium] Genus: [To be described from the Lower Cre­ taceous of North America] Genus: Craspedodon Dollo, 1883 [nomen dubium] Genus: [To be described from the Lower Cre­ = Craspedon Galton, 1980 [sic] taceous of North America] C. lonzeensis Dollo, 1883 (Type) Genus: "" Lambert, 1990 [to be de­ scribed from Japan; based on very scanty ma­ terial]

Ornithischia Seeley, 1888 168 Mesozoic Meanderings #2 Genus: Gravisaums Chabii, 1988 [nomen = Streptospondylus grandis Hulke, 1879 nudum] [nomen dubium] = Gravisaums Norman, 1989 [nomen I. hoggi Owen, 1874 nudum] ?I. exogiramm Fritsch, 1878 [nomen dubium] G. tenerensis Chabii, 1988 (Type) =» Procerosaurus exogiramm (Fritsch, 1878) = Gravisaums tenerensis Norman, 1989 Fritsch, 1905 [nomen dubium] [nomen nudum] = Iguanodon exogyramm Chure & NOTE: This is the stout iguanodontid Mcintosh, 1989 [sic] ("iguanodontide trapu") from Gadoufaoua (Ta- = Procerosaurus exogyramm Chure & quet, 1975; Taquet, 1976). Coined by Fouad Mcintosh, 1989 [sic] Chabii in her 1988 doctoral dissertation, the ge­ I. bemissartensis Boulenger vide van Bene- neric and specific names first appeared in print den, 1881 in the bibliography of The Age of Dinosaurs: = Iguanodon seeleyi Hulke, 1882 Short Courses in Paleontology #2, edited by K. NOTE: This species will be redescribed as Padian and D. Chure, published in 1989 by the the type species of a new genus by G. Paul Paleontological Society. The bibliographic ref­ (pers. comm.). erence is from Norman's article in that volume. /. dawsoni Lydekker, 1888 I.fittoni Lydekker, 1889 Genus: Iguanodon Mantell, 1825 = Iguanodon hollingtoniensis Lydekker, = Heterosaums Cornuel, 1850 [nomen 1889 dubiwn; in part] /. atherfieldensis Hooley, 1924 = Hikanodon Keferstein?, 1825? [nomen = Cetiosaums brachyurus Owen, 1842 oblitum; reference not found] [nomen dubium] = Iguanaodon Galton & H. P. Powell, 1980 = Heterosaums neocomiensis Cornuel, [sic] 1850 [nomen dubium; in part] = Iguanosaums [Anonymous] 1824 [nomen = Vectisaurus valdensis Hulke, 1879 oblitum] (juvenile) = Iguonodon Galton & H. P. Powell, 1980 = Sphenospondylus gracilis Lydekker, 1888 [sic] [nomen dubium] = Iquanadon Stokes, 1988 [sic] = Iguanodon gracilis (Lydekker, 1888) = Iquanodon A. Walker, 1964 [sic] [nomen dubium] = Iguanodon Kalandadze & Kurzanov, 1973 I. orientalis Rozhdestvensky, 1952 [sic] /. ottingeri Galton & Jensen, 1979 (not 1978) = Sphenospondylus Seeley, 1882 [nomen [nomen dubium in Norman & Weishampel, dubium] 1990] = Therosaums Fitzinger, 1843 /. lakotaensis Weishampel & Bjork, 1989 = Vectisaurus Hulke, 1879 (juvenile) /. anglicus Holl 1829 (Type) Genus: Loncosaums Ameghino, 1898 [nomen = Iguanodon anglicum Holl, 1829* dubium] = Iguanodon mantelli von Meyer, 1832 L. argentinus Ameghino, 1898 (Type) = Therosaums mantelli (von Meyer, 1832) = Megalosaums argentinus (Ameghino, = Streptospondylus major Owen, 1842 1898) [nomen dubium] [nomen dubium] NOTE: This species is not a theropod as = Iguanodon major (Owen, 1842) [nomen often classified but an ornithopod (Moinar, dubium] 1980) apparently based on a femur. If it turns = Streptospondylus recentior Owen, 1851 out that the type specimen is a tooth, however, [nomen dubium] then the genus will have to be classified as = Streptospondylus meyeri Owen, 1854 Theropoda incertae sedis (R. E. Moinar, pers. [nomen dubium] comm.). Referred to this family provisionally.

Parainfraclass Archosauria Cope, 1869 169 Ornithischia Seeley, 1888 Genus: Taquet, 1976 zanov, 1974; a large-nosed Mongolian iguano­ = Ouranosaurus Taquet, 1972 [nomen dontid; a photograph of the nearly complete nudum] skull was first published in the guidebook to O. nigeriensis Taquet, 1976 (Type) the USSR paleontological exhibition in Japan = Ouranosaurus nigeriensis Taquet, 1972 in 1973-74; D. Norman, pers. comm.; M. K. [nomen nudum] Brett-Surman, pers. comm.; J. R. Horner, pers. comm.; M. Tanimoto, pers. comm.; Nor­ Genus: Rozhdestvensky, 1966 man & Weishampel, 1990] P. gobiensis Rozhdestvensky, 1966 (Type) P. alashanicus Rozhdestvensky, 1966 Genus: [To be described from the Early Creta­ ceous of western North America; an ornitho­ Genus: Sanpasaurus Young, 1946 pod with elongated neural spines discovered S. yaoi Young, 1946 (Type) by J. A. Jensen; R. A. Long, pers. comm.; B. ?S. imperfectus (Young, 1946) [nomen B. Britt, pers. comm.] dubium] = Gen. indet. imperfectus Young, 1946 Genus: [To be described from central Asia; [nomen dubium] based on remains presently in the collection = Trachodon imperfectus (Young, 1946) of the Paleontological Institute of the USSR [nomen dubium] Academy of Sciences; two or three genera NOTE: The above genus was originally de­ may be present; D. Norman, pers. comm.] scribed as an iguanodontid, but Rozhdestven­ sky, 1966 listed several non-ornithischian char­ acters of the type species and ultimately con­ Family: HADROSAURIDAE Cope, 1869 cluded that Sanpasaurus was a juvenile sauro- pod. Chinese workers have generally not ac­ Census: 24 genera (7 doubtful), cepted this judgment. 40 species (14 doubtful) Genus: [To be described] = Claosauridae Marsh, 1890 = Gadoiosaurus Saito, 1979 [nomen = Hadrosaurinae Lambe, 1918 nudum; juvenile] = Kritosaurines de Lapparent & NOTE: The generic name Gadoiosaurus Lavocat, 1955 was used to label a juvenile ornithopod skele­ = Ornithotarsidae Cope, 1871 ton on display by the Soviet Union in Japan in = Prohadrosauridae von Huene, 1956 1973-74 and was published (without specific = Protrachodontidae Flower, 1928 name) in Wonder of the World's Dinosaurs by = Protrachodontinae Abel, 1919 T. Saito in 1979. That specimen was eventually = Saurolophidae Nopcsa, 1917 referred to Arstanosaurus (P. C. Sereno, pers. = Saurolophinae Brown, 1914 comm.; Ivakhnenko & Korabelnikov, 1987), but this assignment is probably incorrect (D. B. Genus: Amtosaurus Kurzanov & Tumanova, Norman, pers. comm.), and the Gadoiosaurus 1978 [nomen dubium] specimen probably represents a new iguano­ A. magnus Kurzanov & Tumanova, 1978 dontid genus from central Asia. Although (Type) much hadrosaurid material from the Soviet NOTE: The this genus is probably a hadro­ Union has recently been referred to Arstano­ saurid, because the occipital condyle of the saurus, the type specimen of Arstanosaurus ak- type specimen lacks a neck (K. Carpenter, kurganensis is a ceratopsid maxilla (D. Weis- pers. comm.; Coombs, 1990). hampeL, pers. comm.; Nessov & Kaznyshkina, 1989). Genus: Anatotitan Brett-Surman vide Chapman & Brett-Surman, 1990 Genus: [To be described from central Asia, = Anatotitan Brett-Surman, 1988 (chironym) based on skull and skeletal material referred = Anatotitan Norman, 1989 [nomen nudum] to Iguanodon orientalis by Kalandadze & Kur- A. longiceps (Marsh, 1890) n. comb.

Ornithischia Seeiey, 1888 1 Mesozoic Meanderings #2 = Trachodon longiceps Marsh, 1890 = Hadrosaurus agilis Marsh, 1872 = Anatosaums longiceps (Marsh, 1890) = Trachodon agilis (Marsh, 1872) Lull & Wright, 1942 Genus: Diclonius Cope, 1876 [nomen dubium] = Hadrosaurus longiceps (Marsh, 1890) D. pentagonus Cope, 1876 (Type) A. copei (Lull & Wright, 1942) (Type) = Thespesius pentagonus (Cope, 1876) = Anatosaums copei Lull & Wright, 1942 [nomen dubium] = Edmontosaums copei (Lull & Wright, 1942) = Trachodon pentagonus (Cope, 1876) [nomen dubium] = Diclonius mirabilis Cope, 1876 [nomen D. calamarius Cope, 1876 [nomen dubium] dubium; in part] - Thespesius calamarius (Cope, 1876) NOTE: The type specimen at Anatotitan lon­ [nomen dubium] giceps is a long and slender right dentary lack­ = Trachodon calamarius (Cope, 1876) ing teeth (YPM 616; one of the longest hadro- [nomen dubium] saurid dentaries known) that satisfies Brett-Sur- D. perangulatus Cope, 1876 [nomen dubium] man's (1988, 1990) diagnosis of the genus Anat­ = Hadrosaurus perangulatus (Cope, 1876) otitan. As noted in Lull & Wright, 1942, howev­ [nomen dubium] er, YPM 616 differs enough from Anatotitan copei to warrant retaining A longiceps as a dis­ = Tliespesius perangulatus (Cope, 1876) tinct species, which is morphologically interme­ [nomen dubium] diate between the genera Anatotitan and Ed­ - Trachodon perangulatus (Cope, 1876) montosaums. Anatotitan was originally de­ [nomen dubium] scribed in Brett-Surman's (1988) doctoral dis­ Paragenus: Edmontosaums Lambe, 1917 sertation. = Amatosaurus D. A. Russell, 1982 [sic] = Anatosaums Lull & Wright, 1942 Genus: Aralosaums Rozhdestvensky, 1968 = Anotosaums Colbert, 1962 [sic] A. tuberifems Rozhdestvensky, 1968 (Type) = Edmontosaums Stokes, 1988 [sic] = Aralosaums tuberifrons Maryanska, 1977 = Edomontosaums Chapman & Brett-Sur- [sic] man, 1990 [sic] Genus: Brachylophosaums C. M. Sternberg, E. annectens (Marsh, 1892) 1953 = Claosaums annectens Marsh, 1892 = Brachylosaums Czerkas & Czerkas, 1990 = Anatosaums annectens (Marsh, 1892) [sic] Lull & Wright, 1942 B. canadensis C. M. Sternberg, 1953 (Type) = Thespesius annectens (Marsh, 1892) B. goodwini Horner, 1988 = Trachodon annectens (Marsh, 1892) = Claosaums annectans Williston, 1898 Genus: Cionodon Cope, 1874 [nomen dubium] [sic] - Cinodon Cope, 1874 [sic] - Thespesius edmontonensis Gilmore, 1924 C. arctatus Cope, 1874 (Type) = Thespesius edmontoni Gilmore, 1924* = Thespesius arctatus (Cope, 1874) = Anatosaums edmontonensis (Gilmore, [nomen dubium] 1924) Lull & Wright, 1942 = Trachodon arctatus (Cope, 1874) = Anatosaums edmontoni (Gilmore, 1924) [nomen dubium] Lull & Wright, 1942* C. stenopsis Cope, 1875 [nomen dubium] = Edmontosaums edmontonensis (Gil­ = Thespesius stenopsis (Cope, 1875) more, 1924) [nomen dubium] = Edmontosaums edmontoni (Gilmore, - Trachodon stenopsis (Cope, 1875) 1924)* [nomen dubium] = Trachodon edmontonensis (Gilmore, Genus: Claosaums Marsh, 1890 1924) C. agilis (Marsh, 1872) (Type) = Trachodon edmontoni (Gilmore, 1924)* = Tliespesius edmonti Parks, 1935 [sic]

Parainfraclass Archosauria Cope, 1869 171 Ornithischia Seeley, 1888 = Edmontosaums minor Parks, 1935 vide Genus: Hadrosaurus Leidy, 1858 Lull & Wright, 1942 non (Marsh, 1870) = Hadrosaurus C. H. Sternberg, 1909 [sic] E. regalis Lambe, 1917 (Type) - Hodeosaurus Wu, 1985 [sic] = Trachodon atavus Cope, 1871 [nomen = Omithosaurus Riabinin, 1930 [sic] oblitum] = Omithotarsus Cope, 1869 = Agathaumas milo Cope, 1874 [nomen H.fouMi Leidy, 1858 (Type) oblitum] = Trachodon fouMi (Leidy, 1858) = Claosaums affinis Wieland, 1903 = Omithotarsus immanis Cope, 1869 [nomen dubium] = Hadrosaurus foulkei Cope, 1870 [sic] = Trachodon affinis (Wieland, 1903) = Hadrosaurus cavatus Cope, 1871 [nomen dubium] [nomen nudum] E. saskatchewanensis (C. M. Sternberg, 1926) = Trachodon cavatus (Cope, 1871) = Thespesius saskatchewanensis C. M. [nomen nudum] Sternberg, 1926 = Hadrosaurus faulkii Langston, 1960 [sic] = Anatosaurus saskatchewanensis (C. M. H. minor Marsh, 1870 Sternberg, 1926) Lull & Wright, 1942 = Edmontosaums minor (Marsh, 1870) = Trachodon saskatchewanensis (C. M. = Trachodon minor (Marsh, 1870) Sternberg, 1926) ?H. breviceps Marsh, 1889 NOTE: This is a paragenus because it is al­ = Kritosaurus breviceps (Marsh, 1889) most certainly ancestral to the genus Anatotitan. = Trachodon breviceps (Marsh, 1889) NOTE: The above species either belongs in Genus: Gilmoreosaurus Brett-Surman, 1979 the genus or represents a new = Gilmoreosautus Hu & Cheng, 1988 [sic] genus (J. R. Horner, pers. comm.). G. mongoliensis (Gilmore, 1933) (Type) = Mandschurosaums mongoliensis Gil- Genus: "Hironosaurus" Hisa, 1988 [to be de­ more, 1933 scribed from Japan, based on a ?caudal verte­ = Gilmoreosautus mongliensis Hu & bra; in Utan Scientific Magazine #4: 25] Cheng, 1988 [sic] Genus: Cope, 1869 [nomen dubium] = Manschurosaurus mongoliensis Hu & = Hypsibaema von Huene, 1909 [sic] Cheng, 1988 [sic] = Neosaums Gilmore vide Gilmore & = Manschurosaurus monoliensis Hu & Stewart, 1945/Nopcsa, 1923 Cheng, 1988 [sic] = Parrosaurus White, 1973 [sic] Genus: Lambe, 1914 = Parrosaurus Gilmore, 1945 [nomen = Gryposourus Langston, 1965 [51c] dubium] = Gryptosaurus Maryanska & Osmdlska, H. crassicauda Cope, 1869 (Type) 1979 [sic] H. missouriense (Gilmore & Stewart, 1945) G. notabilis Lambe, 1914 (Type) Baird & Horner, 1979 [nomen dubium] = Hadrosaurus notabilis (Lambe, 1914) = Neosaums missouriensis Gilmore vide = Kritosaurus notabilis (Lambe, 1914) Gilmore & Stewart, 1945 [nomen dubium] = Trachodon marginatus Lambe, 1902 — Parrosaurus missouriensis (Gilmore vide [nomen dubium; in part] Gilmore & Stewart, 1945) Gilmore, 1945 = Kritosaurus marginatus (Lambe, 1902) [nomen dubium] [nomen dubium] NOTE: The syntypes of Hypsibema crassi­ = Thespesius marginatus (Lambe, 1902) cauda include theropod material as well as or- [nomen dubium] nithopod material; the lectotype caudal verte­ = Pteropelyx marginata (Lambe, 1902) bra designated by Baird & Horner, 1979, how­ [nomen dubium] ever, represents an indeterminate large hadro- = Pteropelyx marginatus (Lambe, 1902) saurid that by direct comparison is a senior syn­ [nomen dubium]* onym of Parrosaurus. Baird & Horner referred Hypsibema to the Sauropoda, but this assign-

Omithischia Seeley, 1888 172 Mesozoic Meanderings #2 ment is strongly questioned by J. S. Mcintosh NOTE: Recently discovered more complete (pers. comm.) and M. K. Brett-Sunnan (pers. material of this species indicates it is probably comm.). Hypsibema is retained as an indetermi­ an iguanodontid rather than a hadrosaurid (re­ nate hadrosaurid in most recent dinosaur taxon­ ported by Taquet in SVP Bulletin #152). omies {e.g., Weishampel & Horner, 1990). ?M. jiainensis Luo, Zhang & Li, 1983 [nomen nudum] Genus: Kritosaurus Brown, 1910 = Krikotosaums de Lapparent, 1978 [sic] Genus: Microhadrosaurus Dong, 1979 [nomen = Kristosaurus Young, 1958 [sic] dubium] - Kiitosaurs Nagao, 1936 [sic] M. nanshiungensis Dong, 1979 (Type) K. navajovius Brown, 1910 (Type) Genus: Orthomerus Seeley, 1883 [nomen = Hadrosaurus navajovius (Brown, 1910) dubium] = Kritosaurus navajovous Stokes, 1988 [sic] O. dolloi Seeley, 1883 (Type) Genus: Lophorhothon Langston, 1960 (juvenile = dolloi (Seeley, 1883) Prosaurolophusl) ?0. weberi Riabinin, 1941 [nomen dubium] = Lophorothon Horner, 1979 [sic] Paragenus: Prosaurolophus Brown, 1916 = Lophoroton Maryanska & Osmdlska, P. maximus Brown, 1916 1979 [sic] = maximus (Brown, 1916) = Lorphorhothon Glut, 1972 [sic] [New species to be described from the L. atopus Langston, 1960 (Type) Upper Two Medicine Formation of Mon­ Genus: Horner & Makela, 1979 tana] = Maiasauria Stokes, 1988 [sic] NOTE: This is a paragenus because it is al­ = Maiasaurus Browne, 1980 [sic; New York most certainly ancestral to the genus Sauroloph­ Times News Service, February 14,1980] us. M. peeblesorum Horner & Makela, 1979 Genus: Saurolophus Brown, 1912 (Type) = Saurolophus Matthew, 1912 [sic] Genus: Mandschurosaurus Riabinin, 1930 S. osbomi Brown, 1912 (Type) [nomen dubium] ?S. kryschtofovici Riabinin, 1930 [nomen = Manchurisaurus Dong, 1979 [sic] dubium] = Manchurosaurus Nagao, 1936 [sic] S. angustirostris Rozhdestvensky, 1952 = MandchuTosaurus Young, 19S8 [sic] Genus: Secemosaurus Brett-Surman, 1979 = Mandschurisaurus Dong, 1979 [sic] = Mandschurosaus Young, 1958 [sic] S. koemeri Brett-Surman, 1979 (Type) = Mandshurosaurus Young, 1958 [sic] Genus: Hu, 1973 = Manschurosaurus Hu & Cheng, 1988 [sic] = Shantungsaurus Gee, 1989 [sic] M. amurensis (Riabinin, 1925) (Type) S. giganteus Hu, 1973 (Type) = Trachodon amurensis Riabinin, 1925 [nomen dubium] Genus: Wiman, 1929 = Tsintaosaurus Young, 1958 = Trachodon amurense Riabinin, 1925 = Tsintaosourus Young, 1958 [sic] [nomen dubium]* T. sinensis Wiman, 1929 (Type) = Thespesius amurensis (Riabinin, 1925) = Cionodon kysylkumensis Riabinin, 1931 [nomen dubium] [nomen dubium] = Manschurosaurus amurensis Hu & = Cionodon kysylkumense Riabinin, 1931 Cheng, 1988 [sic] [nomen dubium]* = Tracodon amurense Hu & Cheng, 1988 = Thespesius kysylkumensis (Riabinin, [sic] 1931) [nomen dubium] = Mandschurosaurus amwensis = Trachodon kysylkumense (Riabinin, [Anonymous] 1990 [sic] 1931) [nomen dubium] ?M. laosensis Hoffet, 1943 [nomen dubium]

Parainfraclass Archosauria Cope, 1869 173 Ornithischia Seeley, 1888 = Tsintaosaums spinorhinus Young, 1958 Genus: [To be described] = Tanius chingkankouensis Young, 1958 [Type species to be redescribed] NOTE: Taquet (1991) indicates that the tall = Iguanodon hilli Newton, 1892 nasal spike observed in the type specimen of = Craspedodon hilli (Newton, 1892) Tsintaosaums spinorhinus is an artifact of pres­ = Limnosaums hilli (Newton, 1892) ervation, and that the genus Tsintaosaums is ac­ = Orthomerus hilli (Newton, 1892) tually a junior synonym of the flat-headed had- rosaurid Tanius. Cranial and postcranial lambe- Genus: [To be described from Baishin-Tsav, osaurid material incorrectly referred to Tsintao­ Mongolia; Kurzanov, 1976] saums in the original description probably be­ Genus: [To be described from the Senonian of longs to a new or different genus (M. K. Brett- Chubut, Argentina; reported as Paleocene by Surman, pers. comm.; Weishampel & Horner, Casamiquela, 1964; Bonaparte, 1980] 1990). Tanius chingkankouensis is likely based on a subadult individual of Tanius sinensis, Genus: [To be described from the Late Creta­ while Tanius laiyangensis is a Iambeosaund ceous Yacoraite Formation of Argentina; Bo­ that may be a species of that undescribed gen­ naparte, 1980] us whose material was mixed in with Tsintao­ Genus: [To be described from the Oldman For­ saums (Weishampel & Horner, 1990). mation of Alberta, Canada; a solid-crested hadrosaurid; D. Tanke, D. Mclnnes & P. Cur- Genus: Telmatosaums Nopcsa, 1903 (= Or- rie, pers. comm.] thomemsl) = Hecatasaurus Brown, 1910 Genus: [To be described from the St. Mary = Hecatosaums White, 1973 [sic] River Formation of Montana; Horaer, 1983] = Hectasaums Nagao, 1936 [sic] Genus: [To be described from the Lower Two = Limnosaums Nopcsa, 1899/Marsh, 1872 Medicine Formation of Montana; Weisham­ T. transsylvanicus (Nopcsa, 1899) (Type) pel & Horaer, 1990] = Limnosaums transsylvanicus Nopcsa, 1899 Genus: [To be described, based on material re­ = Hecatasaurus transsylvanicus (Nopcsa, ferred to Hadrosaurus minor by Colbert, 1899) 1948; Weishampel & Horner, 1990] = Orthomerus transsylvanicus (Nopcsa, Genus: [To be described, based on material 1899) referred to Hadrosaurus notabilis by Horner, Genus: Thespesius Leidy, 1856 [nomen dubium] 1979; Weishampel & Horner, 1990] T. occidentals Leidy, 1856 (Type) = Hadrosaurus occidental (Leidy, 1856) [nomen dubium] Family: LAMBEOSAURIDAE = Trachodon occidental (Leidy, 1856) von Huene, 1948 [nomen dubium] Census: 10 genera (2 doubtful), Genus: [To be described] [Type species to be redescribed] 19 species (6 doubtful) = Kritosaurus incurvimanus Parks, 1920 = Cheneosauridae von Huene, 1956 = Kritosaurs incmvimanus Nagao, 1936 = Cheneosaurinae Lull & Wright, 1942 [sic] = Parks, 1923 Genus: [To be described] = Stephanosaurinae Lambe, 1920 [Type species to be redescribed] = Trachodontidae Brown, 1914 = Kritosaurus australis Bonaparte, Fran- Genus: Gilmore, 1933 chi, J. Powell & Sepulveda 1984 = Batractosaums Halstead, 1975 [sic] = Kritosaurus australis Bonaparte, 1984 B. johnsoni Gilmore, 1933 (Type) [nomen nudum]

Ornithischia Seeley, 1888 174 Mesozoic Meanderings #2 ?B. prynadai Riabinin, 1937 [nomen dubium] = Cheneosaurus tolmanensis Lambe, 1917 = Tanius prynadai (Riabinin, 1937) [no- (juvenile) men dubium] [New species to be described; D. Weisham- NOTE: The name Paraiguanodon incolapa- pel, pers. coram.] ludis, coined by Barnum Brown in the early NOTE: The assignment of synonymous spe­ 1930s, perhaps for a lecture series, appears on cies to presumed growth stages and sexes in figures of the skeleton of Bactrosaurus johnsoni the above genus is according to Dodson, 1975. in the files of the American Museum of Natu­ Genus: Riabinin, 1937 ral History. = Taxartosaurus Riabinin, 1939 [sic] The type material of Bactrosaurus prynadai = Yaxartosaurus Young, 1958 [sic] is largely indeterminate and may include speci­ J. aralensis Riabinin, 1937 (Type) mens from other genera. = Yaxartosaurus aralensis (Riabinin, 1937) Genus: Barsboldia Maryanska & Osm61ska, = Procheneosaurus convincens Rozhdest- 1981 vensky, 1968 (juvenile) B. sicinskii Maryanska & Osm6lska, 1981 /. fuyunensis Wu, 1984 [nomen dubium in (Type) Weishampel & Horner, 1990] = Yaxartosaurus fuyunensis Wu, 1984* Paragenus: Brown, 1914 [nomen dubium] C. casuarius Brown, 1914 (Type) (male) = casuarius (Brown, 1914) Genus: Parks, 1923 = Corythosaurus excavatus Gilmore, 1923 = Didamodon von Huene, 1956 [sic] (female) = Didanodon Osborn, 1902 = Corythosaurus intermedins Parks, 1923 =• Procheneosaurus Matthew, 1920 [nomen (female) conservandum] = Tetragonosaurus erectofrons Parks, 1931 = Stephanosaurus Lambe, 1914 [nomen (juvenile) dubium] = Procheneosaurus erectofrons (Parks, = Tetragonosaurus Nagao, 1936 [sic] 1931) (juvenile) = Tetragonosauros Parks, 1931 [sic] = Corythosaurus bicristatus Parks, 1935 = Tetragonosaurus Parks, 1931 (female) L. lambei Parks, 1923 (Type) (male) = Corythosaurus brevicristatus Parks, 1935 = Hypacrosaurus lambei (Parks, 1923) (juvenile male) (male) = Tetragonosaurus cranibrevis C. M. = Trachodon marginatus Lambe, 1902 Sternberg, 1935 (juvenile) [nomen dubium; in part] = Procheneosaurus cranibrevis (C. M. = Stephanosaurus marginatus (Lambe, Sternberg, 1935) (juvenile) 1902) [nomen dubium] NOTE: The assignment of synonymous spe­ = Hadrosaurus paucidens Marsh, 1889 cies to presumed growth stages and sexes in [nomen dubium] the above genus is according to Dodson, 1975. = Ceratops paucidens (Marsh, 1889) This is a paragenus because it is almost cer­ [nomen dubium] tainly ancestral to the genera Lambeosaurus = Lambeosaurus paucidens (Marsh, 1889) and Hypacrosaurus. [nomen dubium] - Didanodon Osborn, 1902 (no specific Genus: Hypacrosaurus Brown, 1913 name assigned) = Cheneosaurus Lambe, 1917 = Trachodon altidens Lambe, 1902 = Cheneousaurus Nagao, 1936 [sic] [nomen dubium] - Hypacrosaurs Nagao, 1936 [sic] = Hypocrosaurus C. M. Sternberg, 1953 [sic] = Didanodon altidens (Lambe, 1902) H. altispinus Brown, 1913 (Type) [nomen dubium] = Procheneosaurus altidens (Lambe, 1902) [nomen dubium]

Parainfraclass Archosauria Cope, 1869 175 Ornithischia Seeley, 1888 = Pteropefyx altidens (Lambe, 1902) Hypacrosaurus, Corythosaurus, or Lambeosau­ [nomen dubium] rus because it lacks a skull (M. K. Brett-Sur- = Thespesius altidens (Lambe, 1902) man, pers. comm.). [nomen dubium) Genus: Trachodon Leidy, 1856 [nomen dubium] - Procheneosaurus Matthew, 1920 (no = Tracodon Morris, 1978 [sic] specific name assigned) (juvenile) T. mirabilis Leidy, 1856 (Type) = Tetragonosaurus praeceps Parks, 1931 = Hadrosaurus mirabilis (Leidy, 1856) (juvenile) [nomen dubium] = Procheneosaurus praeceps (Parks, 1931) = Trachodon mirabile Nopcsa, 1917 [sic; (juvenile) may have been confused with Diclonius = Corythosaurus frontalis Parks, 1935 mirabilis Cope, 1876] (juvenile female) TT. cantabrigiensis Lydekker, 1888 [nomen = Lambeosaurus clavinitiaUs C. M. dubium] Sternberg, 1935 (female) = Hadrosaurus cantabrigiensis (Lydekker, L. magnicristatus C. M. Sternberg, 1935 1888) [nomen dubium] (male) = Telmatosaurus cantabrigiensis (Lydek­ = Lambeosaurus magnicristatum C. M. ker, 1888) Olshevsky, 1978 [nomen Sternberg, 1935* (male) dubium] ?L. laacaudus Morris, 1981 TT. selwyni Lambe, 1902 [nomen dubium] NOTE: The assignment of synonymous spe­ = Gryposaurus selwyni (Lambe, 1902) cies to presumed growth stages and sexes in [nomen dubium] the above genus is according to Dodson, 1975. = Pteropefyx selwyni (Lambe, 1902) Genus: Nipponosaurus Nagao, 1936 [nomen dubium] N. sachalinensis Nagao, 1936 (Type) = Thespesius selwyni (Lambe, 1902) NOTE: The above genus is a juvenile lambe- [nomen dubium] osaurid. Adult Asian lambeosaurid genera NOTE: This genus may be a senior synonym should be examined for possible synonymy. of either Prosaurolophus or Corythosaurus (J. R. Horner, pers. comm.). If the type teeth are Genus: Parks, 1922 shown to be birooted, then it may prove to be = Parasaurolophis Stokes, 1988 [sic] ceratopsian (M. K. Brett-Surman, pers. comm.). = Parasaurophus Nagao, 1936 [sic] = Parosaurolophus C. M. Sternberg, 1946 Genus: [To be described; to contain lambeosau­ [sic] rid material incorrectly referred to Tsin- P. walked Parks, 1922 (Type) (male) taosaurus spinorhinus, now synonymized with P. tubicen Wiman, 1931 (male) Tanius sinensis; see note for Tanius] P. cyrtocristatus Ostrom, 1961 (female) [Type species to be redescribed] = Parasaurolophus cyrotocristatus Stokes, = Tanius laiyangensis Zhen, 1976 1988 [sic] NOTE: The assignment of species to pre­ Genus: [To be described from the far-eastern sumed sexes in the above genus is according to USSR by Kurzanov & Bolotsky; indicated in Dodson, 1975. SVP Bulletin #149, June, 1990 (p. 46) as al­ ready described, but paper not yet seen] Genus: Pteropefyx Cope, 1889 [nomen dubium] Genus: [To be described from the Upper Two P. grallipes Cope, 1889 (Type) Medicine Formation of Montana; Weisham- = Thespesius grallipes (Cope, 1889) pel & Horner, 1990] [nomen dubium] = Trachodon grallipes (Cope, 1889) Genus: [To be described from the Judith River [nomen dubium] Formation of Alberta, Canada; a large lambe­ NOTE: The above genus is based on a par­ osaurid with a crest resembling that of Pro­ tial skeleton that cannot be distinguished from cheneosaurus; P. Dodson, pers. comm.]

Ornithischia Seeley, 1888 176 Mesozoic Meanderings #2 Ornithischia incertae sedis Census: 3 doubtful genera, 4 doubtful species Genus: Rhadinosaums Seeley, 1881 [nomen Genus: Thecospondylus Seeley, 1882 [nomen dubium] dubium] R. alcinus Seeley, 1881 (Type) T. homeri Seeley, 1882 (Type) = Struthiosaurus alcinus (Seeley, 1881) NOTE: Generally classified as a theropod, [nomen dubium] this genus may be ornithischian (R. E. Molnar, = Rhadinosaums alcimus Coombs, 1971 pers. comm.). [sic] Genus: Tichosteus Cope, 1877 [nomen dubium] = Struthiosaurus alcimus Coombs, 1971 = Thichosteus Kuhn, 1965 [sic] [sic] T. lucasanus Cope, 1877 (Type) NOTE: This genus has been classified as an IT. aequifacies Cope, 1877 [nomen dubium] ankylosaurian and as an ornithopod, but it NOTE: Generally classified as a theropod, might also be synonymous with Doratodon, a this genus is probably ornithischian (R. E. Mol­ crocodilian. Until further work is published, it nar, pers. comm.). will be left as an ornithischian incertae sedis.

Parainfraclass Archosauria Cope, 1869 177 Ornithischia Seeley, 1888 Notes and New Taxa

Omithischia Seeley, 1888 178 Mesozoic Meanderings #2 Excluded Taxa

he following genera and species have at one NOTE: The above genus is frequently classi­ Ttime or another been classified as non-croc­ fied as a thecodontian incertae sedis but is prob­ odilian archosaurs but are presently regarded ably a trilophosaurid (Charig & Reig, 1970). as outside that domain. Genus: Arctosaums Adams, 1875 [nomen Genus: Aachenosaurus Smets, 1888 [nomen dubium] dubium] A. osbomi Adams, 1875 (Type) A. multidens Smets, 1888 (Type) NOTE: Sometimes considered to be a primi­ NOTE: Originally classified as a hadrosau- tive saurischian dinosaur, the above genus may rid, the type specimen was shown by Dollo, be a trilophosaurid (D. Baird, in Russell, 1984). 1888 to be petrified wood. The shape of the vertebral centrum of Arctosaums, however, is unlike that of typical Genus: Aggiosaurus Ambayrac, 1913 trilophosaurids (R. E. Molnar, pers. comm.). A. nicaeensis Ambayrac, 1913 (Type) = Megalosaurus nicaeensis (Ambayrac, Genus: Bathygnathus Leidy, 1854 1913) B. borealis Leidy, 1854 (Type) NOTE: The above genus was originally clas­ NOTE: The above genus has occasionally sified as a large theropod but is now consid­ been classified as archosaurian, but it is most ered a marine crocodilian (Buffetaut, 1982). likely a sphenacodontid. Genus: Aidachar Nessov, 1981 Genus: Belonochasma Broili, 1939 A.paludaiis Nessov, 1981 (Type) B. aenigmaticum Broili, 1939 (Type) NOTE: Initially described as a pterosaur NOTE: Originally classified as a pterosaur and later given its own family Aidacharidae (and even given its own family, Belonochasma- Nessov, 1982, the above genus is now classified tidae Young, 1964), the type specimen is now as an ichthyodectid fish (Nessov, 1982). known to comprise part of an amiid fish (Mayr, 1973). Genus: Albisaurus Fritsch, 1905 [nomen dubium] Genus: Brasileosaurus von Huene, 1931 A. scutifer Fritsch, 1905 (Type) B. pachecoi von Huene, 1931 (Type) = Iguanodon albinus Fritsch, 1893 [nomen NOTE: The above genus has occasionally dubium] been classified as a thecodontian, but it is now NOTE: Originally classified as an iguano- considered to be a notosuchid crocodilian. dontid, the type specimen is indeterminate and probably non-dinosaurian (J. S. Mcintosh, Genus: Chienkosaums Young, 1942 pers. comm.). = Chienkosaums Colbert, 1961 [sic] C. ceratosauroides Young, 1942 (Type) Genus: Anisodontosaurus Welles, 1947 NOTE: The above genus, frequently classi­ = Anisodonsaums Romer, 1966 [sic] fied as a megalosaurid or ceratosaurid thero­ A. green Welles, 1947 (Type) pod, is based on four teeth, three of which are referable to the crocodilian Hsisosuchus and

Parainfraclass Archosauria Cope, 1869 179 Excluded Taxa the fourth to the theropod Szechuanosaurus NOTE: Occasionally classified as a thero­ (Dong Z., pers. comm.). pod, the above genus is actually a mesosuchian crocodilian. Genus: Chigutisaums Rusconi, 1947 = Icanosaums Rusconi, 1951 Genus: Elachistosuchus Janensch, 1949 C. tunuyanensis Rusconi, 1947 (Type) E. huenei Janensch, 1949 (Type) = Icanosaums rectifrons Rusconi, 1951 NOTE: The above genus, originally classi­ = Otigutisaums tununyanensis Reig, 1%1 fied as a pseudosuchian thecodontian, was re­ [sic] classified as a rhynchosaur by Walker, 1966. It NOTE: The postcranial skeleton of an eryth- was given its own family Elachistosuchidae in rosuchid thecodontian was originally referred von Huene, 1956. to this genus, which is based on a brachyopid Genus: Andrews, 1913 skull, by Rusconi (1951) — an error E. nopcsai Andrews, 1913 (Type) corrected by Shishkin (1961). Tatarinov, (1961) NOTE: The above genus, occasionally re­ referred the genus to Erythrosuchus, and then ferred to as a possible synonym of Heptasteor- Reig (1961) independently erected the genus nis andrewsi in Paul, 1988, is possibly a pele- Cuyosuchus for the postcranial skeleton. Ro- caniform bird (Grigorescu & Kessler, 1980). mer (1966) incorrectly synonymized Icanosau­ ms with Cuyosuchus — it is actually a synonym Genus: Ephoenosaurus [Anonymous] 1839 of the amphibian Chigutisaums, as pointed out [nomen nudum] by Charig & Reig (1970) - and at the same E. solodurensis [Anonymous] 1839 (Type) time synonymized Chigutisaums and Icanosau­ = Ephoenosaurus gracilis [Anonymous] ms with the amphibian genus Pelorocephalus 1839 Cabrera, 1944. Shishkin (1987), however, has NOTE: The above possibly dinosaurian gen­ pointed out differences between Chigutisaums us and two included species appeared in the and Pelorocephalus and considers them to be Allgemeine Schweizer Zeitschrifi, Volume 11, p. distinct amphibian genera. 344. R. Wild (pers. comm.) speculates that the "bone fragment of unusual size," found by a Cetiosaums rigawd Sauvage, 1874 Dr. Hugi, in the newspaper account may have NOTE: The above species is indeterminate become the type specimen of the crocodilian and almost certainly not a sauropod (J. S. Mc­ Machimosaums, which Hugi discovered. intosh, pers. comm.). Genus: Eupodosaurus Boulenger, 1891 Genus: Coionosaums Marsh, 1872 E. longobardicus Boulenger, 1891 (Type) G mudgei Marsh, 1872 (Type) NOTE: Originally classified as a stegosaur, NOTE: The above genus has occasionally the above genus was synonymized with the no- been classified as a small theropod dinosaur, thosaurid genus Lariosaums by von Huene, but the type specimen is actually a portion of 1914. the type specimen of the bird dispar (Feduccia, 1980). Genus: Elzanowski, 1974 G. minuta Elzanowski, 1974 (Type) Ctenosauriscus mgosus (von Huene, 1902) NOTE: Originally described as avian, the = Ctenosaums mgosus von Huene, 1902 above genus has been referred on occasion to NOTE: The above species is referable to the Theropoda. It is presently considered to be the dissorophid amphibian genus Platyhystrix the only known gobipterygiform bird (see, e.g., (D. Baird, pers. comm.). Carroll, 1987). Genus: Doratodon Seeley, 1881 Genus: Gwyneddosaurus Bock, 1945 [nomen = Diratodon von Huene, 1909 [sic] dubium] D. carcharidens (Bunzel, 1871) (Type) G. erici Bock, 1945 (Type) = Crocodilus carcharidens Bunzel, 1871 NOTE: Originally classified as a small thero­ pod, the above genus was subsequently classi-

Excluded Taxa 180 Mesozoic Meanderings #2 fied as an askeptosaurid prolacertilian by von genus Palaeosauriscus Kuhn, 1959, but because Huene, 1956. Olsen & Flynn, 1989, however, it is a nomen nudum, this question cannot be have determined that the type specimen is a decided. It has also been suggested in the litera­ mixture of Tanytrachelos (a tanystropheid) re­ ture that it is a captorhinomorph (R. E. Mol­ mains and coelacanth scrap. nar, pers. comm.). Hadrosaums tripos Cope, 1869 Genus: Pneumatoarthrus Cope, 1870 = Trachodon tripos (Cope, 1869) = Pneumatarthrus Cope, 1872 [sic] NOTE: The above species is based on the P. petoreus Cope, 1870 (Type) partial skeleton of a Pliocene whale (Baird & NOTE: Baird, 1978, conclusively demonstrat­ Horner, 1979). ed that the above genus, originally described as dinosaurian but subsequently referred, on occa­ Genus: Heleosaums Broom, 1907 sion, to the Chelonia, is actually a protostegjd H. scholtzi Broom, 1907 (Type) turtle and could well be a senior synonym of NOTE: Generally considered to be an eo- the genus Archelon. suchian, this genus is classified as Thecodontia incertae sedis by Carroll (1988), who considers Genus: Procerosaurus von Huene, 1902 it a possible early archosaur. P. cruralis von Huene, 1902 (Type) NOTE: The above genus, sometimes classi­ Genus: Laomis Marsh, 1870 fied as ornithischian, is based on a femur of the L. edvardsianus Marsh, 1870 (Type) prolacertilian Tanystropheus conspicuus (von NOTE: Originally described as avian, the Huene, 1910; see Wild, 1973). above genus has on occasion been referred to the Pterosauria, but a recent restudy by S. Ol­ Genus: Rhabdopelix von Huene, 1921 [nomen son indicates it is a charadriiform bird. dubium] R. longispinis (Cope, 1869) (Type) Genus: Macelognathus Marsh, 1884 = Pterodactylus longispinis Cope, 1869 = Maceilognathus von Huene, 1956 [sic] [nomen dubium] = Marcellognathus Romer, 1966 [sic] NOTE: The type specimen of the above gen­ M. vagans Marsh, 1884 (Type) us, now lost, is composite, but the most diagnos­ NOTE: Originally classified in its own reptil­ tic portions appear to be referable to Icarosau- ian order and considered on occasion to be a rus siefkeri, a species of gliding lacertilian (Col­ small dinosaur, the above genus is now placed bert, 1966; D. Baird, pers. comm.). Olsen & in its own crocodilian family (Ostrom, 1961). Flynn, 1989, regard some of the remains of the Megalosaums mersensis de Lapparent, 1955 type specimen as referable to the tanystropheid NOTE: This species of Megalosaums is Tanytrachelos. based on three teeth and 23 vertebrae that are Genus: Haughton, 1932 now thought to belong to a teleosaurid crocodil­ S. stockleyi Haughton, 1932 (Type) ian (Chabli, 1985). NOTE: Referred to the Thecodontia in its Megalosaums schnaitheimii Bunzel, 1871 own family Stenaulorhynchidae Kuhn, 1933, NOTE: This species is probably a metrio- the above genus is presently considered to be a rhynchid crocodilian (R. E. Molnar, pers. rhynchosaur. comm.). Genus: Stereosaurus Seeley, 1869 [nomen Palaeosauriscus stembergii (Fitzinger, 1843) dubium] [nomen nudum] S. platyomus Seeley, 1869 (Type) = Palaeosaurus stembergii Fitzinger, 1843 S. cratynotus Seeley, 1869 [nomen dubium] [nomen nudum] S. stenomus Seeley, 1869 [nomen dubium] NOTE: The above species may belong to NOTE: The above genus and its three spe­ the crocodilian genus Palaeosaurus Geoffroy cies have been mentioned as possible dinosaurs Saint-Hilaire, 1833 and not the thecodontian

Parainf raclass Archosauria Cope, 1869 181 Excluded Taxa (Olshevsky, 1978), but they are probably plesio- Thecodontosaums primus von Huene, 1908 saurian (J. S. Mcintosh, pers. comm.). = Thecodontosaums primus von Huene, 1905 [nomen nudum] Genus: Succinodon von Huene, 1941 S. putzeri von Huene, 1941 (Type) NOTE: The above species is a junior syno­ NOTE: Said to be based on sauropod teeth, nym of the prolacertilian Tanystropheus antiqu- this genus is now thought to consist of filled us (Wild, 1973). borings of bivalve molluscs of the genus Ku- Genus: Tribelesodon Bassani, 1886 phus (Pozaryska & Pugaczewska, 1981). T. longobardicus Bassani, 1886 (Type) NOTE: Thought to be a Triassic pterosaur Genus: Suitanuvaisia Nessov, 1981 by ZitteL, 1890 and others, the above genus is S. antique Nessov, 1981 (Type) referable to the prolacertilian genus Tanystro­ NOTE: Initially classified as a pterosaur pheus (Wild, 1973). and later placed in the family Aidacharidae Nessov, 1982, the above genus is now classified Genus: Unicerosaums Armstrong, 1987 [nomen as an ichthyodectid fish (Nessov, 1982). nudum] No type species designated Genus: Tanystropheus von Meyer, 1855 NOTE: The above genus is mentioned in an = Tanistropheus Alberti, 1864 [sic] article (J. R. Armstrong, 1987: Creation/Evolu­ = Tanystrophaeus Cope, 1888 [sic] tion Newsletter 7(5): p. 21) debunking an exhibi­ = Tanystrophyaeus von Huene, 1914 [sic] tion in a creationist "museum" (a trailer, called = Tranystropheus Wild, 1980 [sic] the Creation Evidences Museum, operated by T. conspicuus von Meyer, 1855 (Type) the Rev. Dr. Carl Baugh). The name appears and others... on the label of an exhibited fossil bone said to NOTE: The above genus, containing much be a dinosaur horn that could "be folded back material previously classified as archosaurian, like a jack knife blade."'Armstrong speculates is actually prolacertilian. For a list of species that the specimen is actually a fin spine of a and synonymies within this genus, see Wild, huge fish, such as Portheus. 1973. Genus: Wyleyia Harrison & C. A. Walker, 1973 Genus: Tapinosaums Lennier, 1887 [nomen [nomen dubium] nudum] W. valdensis Harrison & C. A. Walker, 1973 No type species named (Type) NOTE: The name of this genus, in a caption NOTE: Originally classified as avian, this to a figure of fragmentary but large remains genus has been considered to be a small thero- from the of Normandy, is proba­ pod (Brodkorb, 1978; Olshevsky, 1979; Feduc- bly a misspelling of Tapinocephalus, a therap- cia, 1980). It may now be classified as an enan- sid. Classified as Sauropoda incertae sedis in tiornithid bird (R. E. Molnar, pers. comm.), al­ Steel, 1970, the figured remains, as well as oth­ though it is still listed as an indeterminate ther- er specimens referred to this genus by Rabeck opod in Norman, 1990. (1923), are probably plesiosaurian (R. E. Mol- nar, pers. comm.; Buffetaut, Cuny & Le Genus: Yezosaums Obata & Muramoto, 1977 Loeuff, 1991). [nomen nudum] Y. mikasaensis Obata & Muramoto, 1977 Thecodontosaums latespinatus von Huene, 1908 = Thecodontosaums latespinatus von (Type) NOTE: Appearing without description in a Huene, 1905 [nomen nudum] short article on theropod dinosaurs, the speci­ NOTE: The above species is a junior syno­ men identified by the above generic and specif­ nym of the prolacertilian Tanystropheus con­ ic names is apparently mosasaurian (D. Chure, spicuus (Wild, 1973). pers. comm.).

Excluded Taxa 182 Mesozoic Meanderings #2 References

HE FOLLOWING REFERENCES pertain Arcucci, A., 1986. "Nuevos Materiales y Rein- Tsolely to the introductory textual sections. terpretacion de Lagerpeton chanarensis Ro- To provide references for each individual taxon mer (Thecodontia, Lagerpetonidae nov.) del in die archosaur list would more than double Triassico Medio de la Rioja, Argentina," this book's size (and production costs) but Ameghiniana 23(3/4): 233-242. would just duplicate information readily avail­ Arcucci, A^ 1987. "Un Nuevo Lagosuchidae able elsewhere. In most cases, specifying au- (Thecodontia — Pseudosuchia) de la Fauna de dior and year of a taxon manageably restricts los Chanares (edad Reptil Chanarense, Triasi- the time required to locate the reference in co Medio), La Rioja, Argentina," Ameghini­ standard bibliographies. For dinosaurs, I strong­ ana 24: 89-94. ly recommend Chure & Mcintosh's monumen­ tal dinosaur bibliography (1989) and the enor­ Bakker, R. T.,, 1975. "Dinosaur Renaissance," mous bibliographic section of the landmark Scientific American 232(4): 58-78. volume The Dinosauria (Weishampel, Dodson & Osmdlska, eds., 1990). For pterosaurs, the Bakker, R. T., 1980. "Dinosaur Heresy-Dino­ footnote references in the superlative semipop- saur Renaissance: Why We Need Endother- ular study by Wellnhofer (1991) provide an ex­ mic Archosaurs for a Comprehensive Theory cellent entry into the literature. References to of Bioenergetic Evolution," Chapter 12 of the remaining archosaurs may be found in the Thomas & Olson, eds., 1980: 351-462. bibliography sections of Chang, Krebs, Sues & Bakker, R. T., 1986. 77ie Dinosaur Heresies: Westphal, 1976 and Benton, ed., 1988. Of New Theories Unlocking the Mystery of the Di­ course, references to some of die taxa in the nosaurs and Their Extinction, New York, Wil­ table can be found among the works listed here. liam Morrow and Co., Inc.: 482 pp. In the rush of preparing the first printing of this work in time for the 1991 SVP annual meet­ Bakker, R. T. & Galton, P. M., 1974. "Dino­ ing, it was impossible for me to ensure that all saur Monophyly and a New Class of Verte­ textual citations were included below. My apol­ brates," Nature 248:168-172. ogies to authors whose works may thus have Bakker, R. T., Williams, M. & Currie, P. J., been inadvertendy omitted; any necessary cor­ 1988. "Nanotyrannus, a new genus of pygmy rections will appear in subsequent printings. tyrannosaurid from the latest Cretaceous of Montana," Hunteria 7(5): 1-30. [Anonymous] 1986. Claws: The Story (So Far) of a Great British Dinosaur, Baryonyx Walk­ Balda, R. P., Caple, G. & Willis, W. tL, 1985. ed, British Museum (Natural History) publica­ "Comparison of the Gliding to Flapping Se­ tion: 18 pp. quence with the Flapping to Gliding Se­ quence," in Hecht, Ostrom, Viohl & Welln­ [Anonymous] 1986? "A Brief Display Introduc­ hofer, eds., 1985: 267-277. tion of the ," Zi- gong Dinosaur Museum publication: 4 pp. Ballew, K. L,, 1989. "A phylogenetic analysis of Phytosauria from the Late Triassic of the

Parainf raclass Archosauria Cope, 1869 183 References western United States," in Lucas & Hunt, pel, Dodson & Osmolska, eds., 1990: 11-30. eds., 1989: 309-339. Benton, M. J., 1990b. The Reign of the Reptiles, Barsbold, R-, 1976. "[On the evolution and sys- New York, Crescent Books: 144 pp. tematics of the late Mesozoic dinosaurs]," Do- Benton, M. J. & Clark, J. M., 1988. "Archo- klady Akademii Nauk SSSR 226: 685-688 [in saur phylogeny and the relationships of the Russian]. Crocodylia," chapter 8 of Benton, ed., 1988: Barsbold, R. & Maryanska, T„ 1990. "Segno- 295-338. sauria," Chapter 18 of Weishampel, Dodson Bock, W. J., 1985. "The Arboreal Theory for & Osm61ska, eds., 1990: 408-415. the Origin of Birds," in Hecht, Ostrom, Viohl Barsbold, R-, Maryanska, T. & Osm61ska, H., & Wellnhofer, eds., 1985: 199-207. 1990. "Oviraptorosauria," Chapter 10 of Weis­ Bonaparte, J. F., 1971a. "Cenitosaurus binsfeldi hampel, Dodson & Osm61ska, eds., 1990: 249- Price, Tipo de una Nueva Familia de Teco- 259. dontes (Pseudosuchia — Proterochampsia)," Barsbold, R. & Osmolska, H., 1990. "Ornitho- An. Acad, brasil. Gene. (1971) 43 (Suplemen- mimosauria," Chapter 8 of Weishampel, Dod­ to): 417-422. son & Osm61ska, eds., 1990: 225-244. Bonaparte, J. F., 1971b. "Los Tetrapodos del Basilewsky, P., 1950. "Revision Generale des Sector Superior de la Formacion Los Colora- Harpalinae d'Afrique et de Madagascar (Co- dos, La Rioja, Argentina (Triasico Superior), leoptera Carabidae)," Annates du Musee du I Parte," Opera Lilloana 22: 1-183. Congo Beige Tervuren (Belgigue), Serie in 8°' Bonaparte, J. F., 1976. "Pisanosaurus mertii Ca- Sciences Geologiques 6: 224 pp. + IX pi. samiquela and the Origin of the Ornithis- Baur, G., 1890. "Professor Marsh on Hallopus chia," Journal of Paleontology 50(5): 808-820. and other dinosaurs," American Naturalist 24: Bonaparte, J. F., 1982. "Classification of the 569-571. Thecodontia," Geobios Mimoire Special 6: 99— Bennett, S. C, 1990. "A pterodactyloid ptero­ 112. saur from the Santana Formation of Brazil: Bonaparte, J. F., 1984. "Locomotion in rauisu- Implications for terrestrial locomotion," Jour­ chid thecodonts," Journal of Vertebrate Paleon­ nal of Vertebrate Paleontology 10(1): 80-85. tology 5(4): 210-218. Benton, M. J., 1985. "Classification and Phytog­ Bonaparte, J. F., 1986a. "Les Dinosaures (Car- eny of the Diapsid Reptiles," Zoological Jour­ nosaures, Allosaurid6s, Sauropodes, C6tiosau- nal of the Linnaean Society 84: 97-164. rides) du Jurassique Moyen de Cerro C6ndor Benton, M. J., 1986a. "The Late Triassic rep­ (Chubut, Argentine)," [first part] Annates de tile Teratosaurus — di rauisuchian, not a dino­ Paliontologie (Vert.-Invert.) 72(3): 247-289. saur," Paleontology 29: 293-301. Bonaparte, J. F., 1986b. "The early radiation Benton, M. J., 1986b. "The Late Triassic tetra- and phylogenetic relationships of the Jurassic pod extinction events," Chapter 24 of Padian, sauropod dinosaurs, based on vertebral anato­ ed., 1986b: 303-320. my," Chapter 19 of Padian, ed., 1986b: 247- 258. Benton, M. J_ ed. 1988. The Phytogeny and Classification of the , Volume 1: Am­ Bonaparte, J. F. & Novas, F. E., 1985. uAbeli- phibians, Reptiles, Birds, Systematics Associa­ saurus comahuensis, n. g., n. sp., Carnosauria tion Special Volume #35A, Oxford, Claren­ del Cretacico Tardio de Patagonia," Ameghin- don Press: x + 377 pp. iana 21(2-4): 259-265. Benton, M. J., 1990a. "Origin and Interrelation­ ships of Dinosaurs," Chapter 1 of Weisham-

References 184 Mesozoic Meanderings #2 Boucot, A. J., 1979. "Cladistics: Is It Really Dif­ Museum: 58-79. ferent from Classical Taxonomy?" in Cracraft Carroll, R. L*, 1988. Vertebrate Paleontology & Eldredge, eds., 1979: 199-210. and Evolution, New York, W. H. Freeman & Britt, B. B., 1991. "Theropods of Dry Mesa Co.: xiv + 698 pp. Quarry (Morrison Formation, Late Jurassic), Carroll, R. L. & Dong Z., 1991. "Hupehsuchus, Colorado, with Emphasis on the Osteology of an enigmatic aquatic reptile from the Triassic Torvosaurus tanneri," Brigham Young Univer­ of China, and the problem of establishing rela­ sity Geology Studies 37: 1-72. tionships," Philosophical Transactions of the Broili, F., 1927. "Ein Rhamphorhynchus mit Royal Society of London, Series B, Biological Spuren von Haarbedeckung," Sitzungsberichte Sciences. der Bayerischen Akademie der Wissenschaften, Chao, S., 1983. "Phylogeny and Evolutionary mathematische-naturwissenschaftliche Abteil- Stages of Dinosauria," Acta Palaeontologia Po- ung 1927: 49-67. lonica 28(1/2): 295-306 [author's name Broom, R^ 1906. "On the South African diapto- spelled Zhao Xijin in this article]. saurian reptile " Proceedings of the Charig, A. J., 1972. "The evolution of the ar- Zoological Society of London 1906(2): 591- chosaur pelvis and hindlimb: an explanation 600. in functional terms," in Studies in Vertebrate Bufletaut, E., 1989. "Evolution [of Croco­ Evolution, K. A. Joysey & T. S. Kemp, eds., diles]," in Ross & Garnett, eds., 1989: 26-39. New York, Winchester Press: 121-155. Bufletaut, E. & Ingavat, R^ 1986. "Unusual Charig, A. J., 1976a. "Introduction: Subclass theropod teeth from the Upper Jurassic of Archosauria Cope 1869," in Charig, Krebs, Phu Wiang, northeastern Thailand," Rev. Sues & Westphal, 1976: 1-6. Paleobiologie 5(2): 217-220. Charig, A. J„ 1976b. "Order Thecodontia Buhler, P., 1985. "On the Morphology of the Owen 1859," in Charig, Krebs, Sues & West­ Skull of Archaeopteryx," in Hecht, Ostrom, phal, 1976: 7-10. Viohl & Wellnhofer, eds., 1985: 135-140. Charig, A. J., 1982. "Problems in dinosaur phy­ Cailison, G. & Quimby, H. M., 1984. "Tiny Di­ togeny: a reasoned approach to their attempt­ nosaurs: Are They Fully Grown?" Journal of ed solution," Geobios Memoire Special 6: 113- Vertebrate Paleontology 3(4): 200-209. 126. Calzavara, M., Muscio, G. & Wild, R^ 1980. Charig, A. J., 1985. "Analysis of the Several "Megalancosaurus preonensis n.g., n.sp., A Problems Associated with Archaeopteryx" in New Reptile from the Norian of Italy, " Gor- Hecht, Ostrom, Viohl & Wellnhofer, eds., tania—Atd del Museo Friulano di Storia 1985: 21-30. Naturale 2(1980): 49-63. Charig, A. J., Attridge, J. & Crompton, A. W., Camp, C. L. & Banks, M. R^ 1978. "A protero- 1965. "On the origin of the sauropods and the suchian reptile from the Early Triassic of Tas­ classification of the Saurischia," Proceedings mania," Alcheringa 2:143-158. of the Linnaean Society of London 176: 197- 221. Carpenter, K. & Currie, P. J., eds., 1990. Dino­ saur Systematics: Approaches and Perspectives, Charig, A. J. & Milner, A. C, 1986. "Baryonyx, Cambridge University Press: xvi + 318 pp. a remarkable new theropod dinosaur," Nature 324: 359-361. Carroll, R. L*, 1976. "Eosuchians and the Ori­ gin of Archosaurs," in Churcher, C. S., ed., Charig, A. J. & Milner, A. C, 1990. "The syste­ Athlon: Essays in Palaeontology in Honour of matic position of Baryonyx walkeri, in the light Loris Shano Russell, Toronto, Royal Ontario of Gauthier's reclassification of the Theropo-

Parainfraclass Archosauria Cope, 1869 185 References da," Chapter 9 of Carpenter & Currie, eds., Coombs, W. P., Jr. & Maryanska, T., 1990. 1990: 127-140. "Ankylosauria," Chapter 22 of Weishampel, Chang, A. J. & Newman, B. FL, 1962. "Foot­ Dodson & Osm61ska, eds., 1990: 456-483. prints in the Purbeck," New Scientist #285 Coombs, W. P., Jr., Weishampel, D. B. & Wit- (May 3,1962): 234-235. mer, L. M., 1990. "Basal Thyreophora," Chap­ ter 20 of Weishampel, Dodson & Osmolska, Charig, A. J. & Reig, O. A^ 1970. "The classifi­ eds., 1990: 427-434. cation of the Proterosuchia," Biological Jour­ nal of the Linnaean Society 2: 125-171. Cooper, M. R^ 1985. "A Revision of the Orni- thischian Dinosaur Kangnasaurus coetzeei Charig, A. J. & Sues, H.-D., 1976. "Proterosu­ Haughton, with a Classification of the Orni- chia," in Charig, Krebs, Sues & Westphal, thischia," Annals of the South African Muse­ 1976:11-39 um 95(8): 281-317. Charig, A. J., Krebs, B., Sues, H.-D. & West­ Cope, E. D., 1870. "Synopsis of the extinct Ba- phal, F., 1976. "Thecodontia," Handbuch der trachia and Reptilia of North America," Tran­ Palaoherpetologie, Part 13, O. Kuhn, ed., Stutt­ sactions of the American Philosophical Society gart, Gustav Fischer Verlag: 137 pp. [See also 14: 1_147. citations for individual authors]. Cracraft, J., 1988. "The major clades of birds," Chatterjee, S., 1978. "A Primitive Parasuchid chapter 9 of Benton, ed., 1988: 339-361. (Phytosaur) Reptile from the Upper Triassic Maleri Formation of India," Paleontology Cracraft, J. & Eldredge, N., eds., 1979. Phyloge- 21(1): 83-127. netic Analysis and Paleontology, New York, Columbia University Press: 233 pp. Chatterjee, S., 1985. "Postosuchus, a new theco- dontian reptile from the Triassic of Texas and Crush, J. P., 1984. "A late Upper Triassic sphe- the origin of tyrannosaurs," Philosophical nosuchid crocodilian from Wales," Paleontol­ Transactions of the Royal Society of London, ogy 27:131-157. Series B, Biological Sciences, 309: 395-460. Currie, P. J., 1987. "Bird-like characteristics of Chatterjee, S~, 1991. "Cranial anatomy and rela­ the jaws and teeth of troodontid theropods," tionships of a new Triassic bird from Texas," Journal of Vertebrate Paleontology 7(1): 72-81. Philosophical Transactions of the Royal Soci­ Currie, P. J., 1990. "Elmisauridae," Chapter 9 ety of London, Series B, Biological Sciences, of Weishampel, Dodson & Osmolska, eds., 532(1265): 277-346. 1990: 245-248. Chiappe, L. M., 1990. "A Flightless Bird from Dames, W., 1884. "Vorlegung eines Zahnes the Late Cretaceous of Patagonia (Argen­ von Megalosaurus aus dem Wealden des Dei- tina)," Archosaurian Articulations 7(10): 73- sters," Sitzungsberichte der Gesellschaft natur- 77. forschender Freunde zu Berlin 1884: 186-188. Chure, D. J. & Mcintosh, J. S., 1989. A Bibliog­ Das-Gupta, H. C, 1931. "On a new Theropod raphy of the Dinosauria (Exclusive of the Dinosaur (Orthogoniosaurus Matleyi, n. gen. Aves) 1677-1986, Museum of Western Colora­ et n. sp.) from the Lameta beds of Jubbul- do Paleontology Series #1: xii + 226 pp. pore," Journal of the Asiatic Society of Bengal, Colbert. E. H., 1989. "The Triassic Dinosaur New Series, 26(1): 367-369. Coelophysis," Museum of Northern Arizona Denton, R. FL, 1990. "A revision of the thero­ Bulletin 57, Flagstaff, Arizona: xv + 160 pp. pod Dryptosaurus aquilunguis (Cope 1869)," Coombs, W. P., Jr., 1978. "Theoretical aspects Supplement to Journal of Vertebrate Paleontol­ of cursorial adaptations in dinosaurs," ogy 10(3), abstract #49 of paper presented at Quarterly Review of Biology 53: 393-418. 1990 SVP annual meeting.

References 186 Mesozoic Meanderings #2 Dodsoo, P., 1986. "Avaceratops lammersi: A EUenberger, P., 1974. "Contribution a la classi­ New Ceratopsid from the Judith River Forma­ fication des pistes des vertebres du Trias: Les tion of Montana," Proceedings of The Acade­ types du Stormberg d'Afrique du Sud (II-eme my of Natural Sciences of Philadelphia 138(2): partie: Le Stormberg Superieur — I. Le bi- 305-317. ome de la zone B/l ou niveau de Moyeni: ses biocenoses),'" Paleovertebrata Memoire Extra­ Dodson, P., 1990s. "Counting dinosaurs: How ordinaire 1974, MontpeUier. many kinds were there?" Proceedings of the National Academy of Sciences USA 87: 7608- EUenberger, P., 1977. "Quelques pr6cisions sur 7612. 1'anatomie et la place systematique tres speci- ale de Cosesaurus aviceps (Ladinien super­ Dodson, P., 1990b. "Marginocephalia," in Weis- ieur de Montral, Catalogne)," Cuademos de hampel, Dodson & Osm61ska, eds., 1990: 562- Geologia Ibirica 4:169-188. 563. EUenberger, P., 1978. "L'origine des Oiseaux. Dodson, P. & Currie, P. J., 1990. "Neoceratop- Historique et methodes nouvelles. Les pro- sia," Chapter 29 of Weishampel, Dodson & blemes des Archaeornithes. La venue au jour Osm61ska, eds., 1990: 593-618. de Cosesaurus aviceps (Muschelkalk super­ Efremov, I. A^ 1940. "Die Mesenfauna der per- ieur)," Mem. Trav. E.P.H.E. Inst. MontpeUier mischen Reptilien," Neues Jahrbuch der Miner- 4: 91-117. alogie, Geologic, und Paldontologie, Abteilung EUenberger, P. & de Villalta, J. F., 1974. "Sur B, 84: 379-466. la prdsence d'un ancetre probable des Oi­ Efremov, I. A, 1955. "Katalog mestonakhozh- seaux dans le Muschelkalk superieur de Cata­ denii permskikh i triasovikh nazemnikh pozvo- logne (Espagne). Note prdliminaire," Acta Ge- nochnikh na territorii SSSR [A Catalog of oldgica Hispanica 9(5): 162-168. Sites of Permian and Triassic Terrestrial Ver­ Evans, S. E., 1988. "The early history and rela­ tebrates in the Territory of the USSR]," Tran­ tionships of the Diapsida," in Benton, ed., sactions (Trudy) of the Paleontoiogical Insti­ 1988: 221-260. tute of the USSR Academy of Sciences 46: 1- 185. Frey, E., 1988a. "Anatomie der Kdrperstammes von Alligator mississipiensis Daudin," Stut- Eldredge, N. & Cracraft, J., 1980. Phylogenetic tgarter Beitrage zur Naturkunde, Serie A Patterns and the Evolutionary Process: Method (Biologie) #424: 1-106. and Theory in Comparative Biology, New York, Columbia University Press: x + 349 pp. Frey, E., 19881b. "Das Tragsystem der Krokodi- le — eine biomechanische und phylogenetische EUenberger, P., 1970. "Les niveaux paleontolo- Analyse," Stuttgarter Beitrage zur Naturkunde, giques de premiere apparition des Mammi- Serie A (Biologie) #426: 1-60. feres Primordiaux en Afrique du Sud et lew Ichnologie: Establissement de zones stratigra- Gabriel, D. L. & Berghaus, C. B., 1988. "Three phiques detaillees dans le Stormberg du Leso­ New Specimens of Stygimoloch spinifer (Orni- tho (Afrique du Sud, Trias Superieur a Juras- thischia; Pachycephalosauria) and Behavioral sique)," in Haughton, S. H., ed., I.U.G.S., 2nd Inferences Based on Cranial Morphology," In­ Symposium on Stratigraphy and Pa­ ternational Symposium on Vertebrate Behavior leontology, Pretoria, Council for Scientific and as Derived from the Fossil Record, abstract. Industrial Research: 343-370. Galton, P. M., 1972. "Classification and evolu­ EUenberger, P., 1972. "Contribution a la classi­ tion of ornithopod dinosaurs," Nature 239: fication des pistes des vertebres du Trias: Les 464-466. types du Stormberg d'Afrique du Sud (I)," Pa- Galton, P. M., 1974a. "The ornithischian dino­ leovertebrata Memoire Extraordinaire 1972, saur Hypsilophodon from the Wealden of the Montpellier: 152 pp.

Parainfraclass Archosauria Cope, 1869 187 References Isle of Wight," Bulletin of the British Museum Origin of Birds and their Flight," in Hecht, (Natural History) Geology 25:1-152. Ostrom, Viohl & Wellnhofer, eds., 1985: 185- Galton, P. M„ 1974b. "Notes on Thescelosau- 197. rus, a conservative ornithopod dinosaur from Gifiln, E. B., Gabriel, D. L. & Johnson, R. E., the Upper Cretaceous of North America, 1987. "A New Pachycephalosaurid Skull (Or- with comments on ornithopod classification," nithischia) from the Cretaceous Hell Creek Journal of Paleontology 48:1048-1067. Formation of Montana," Journal of Vertebrate Paleontology 7(4): 398-407. Galton, P. ML, 1985a. "The poposaurid theco- dontian Teratosaurus suevicus v. Meyer, plus Gillette, D. D. & Lockley, M. G., eds., 1989. Di­ referred specimens mostly based on prosauro- nosaur Tracks and Traces, Cambridge, Cam­ pod dinosaurs, from the Middle Stubensand- bridge University Press: xviii + 454 pp. stein (Upper Triassic) of Nordwurttemburg," Gilmore, C. W„ 1920. "Osteology of the Carniv­ Stuttgarter Beitrage zur Naturkunde, Serie B orous Dinosauria in the United States Nation­ (Geologie und Palaontologie) 116: 1-29. al Museum, with special reference to the gen­ Galton, P. M., 1985b. "Notes on the Melanoro- era Antrodemus (Allosaurus) and Ceratosau- sauridae, a Family of Large Prosauropod Di­ rus," Smithsonian Institution United States Na­ nosaurs (Saurischia: Sauropodomorpha)," Ge- tional Museum Bulletin 110: XI + 159 pp., 36 obios 18(5): 671-676. pi. Galton, P. M., 1990a. "Basal Sauropodomor­ Haubold, H., 1990. "Dinosaurs and Fluctuating pha—Prosauropoda," Chapter 15 of Weis- Sea Levels During the Mesozoic," Historical hampel, Dodson & Osm61ska, eds., 1990: 320- Biology 4(2): 75-106. 344. Haubold, H. & Buffetaut, E., 1987. "Une no- Galton, P. M., 1990b. "Stegosauria," Chapter velle iinterprdtation de Longisquama insignis, 21 of Weishampel, Dodson & Osm61ska, eds., reptile dnigmatique du Trias sup€rieur d'Asie 1990: 435-455. centrale [A new interpretation of Longisqua­ ma insignis, an enigmatic reptile from the Galton, P. M. & Van Heerden, J., 1985. "Par­ Upper Triassic of Central Asia]," C. R. Acad. tial Hindlimb of Blikanasaurus cromptoni n. Set Paris 305, Serie II: 65-70. gen. and n. sp., Representing a New Family of Prosauropod Dinosaurs from the Upper Hecht, M. KL, Ostrom, J. H., Vlohl, G. & Triassic of South Africa," Geobios 18(4): 509- Wellnhofer, P., eds., 1985. 77ie Beginnings of 516. Birds: Proceedings of the International Archae- opteryx Conference Eichstdtt 1984, Eichstatt, Gans, C, Darevski, I. & Tatarinov, L. P., 1987. Freunde des Jura-Museums Eichstatt: 382 pp. "Sharovipteryx, a reptilian glider?" Paleobiol­ + 2 pi. ogy 13(4): 415-^26. Heilmaian, G., 1927. 77ic Origin of Birds, New Gauthier, J., 1986a. A Cladistic Analysis of the York, D. Appleton & Co.: viii + 210 pp. Higher Systematic Categories of the Diapsida, 1984 Ph.D. dissertation, University of Califor­ Hennig, W., 1966. Phylogenetic Systematics, Ur- nia at Berkeley, published by University Mi­ bana, Illinois, University of Illinois Press: 263 crofilms International, Ann Arbor, Michigan: pp. vii + 564 pp. HinchlilTe, J. R^ 1977. "The chondrogenetic Gauthier, J., 1986b. "Saurischian Monophyly pattern in chick limb morphogenesis: a prob­ and the Origin of Birds," in Padian, ed., 1986: lem of development and evolution," in Ede, 1-55. D. A., Hinchliffe, J. R. & Balls, M., eds., Ver­ tebrate Limb and Somite Morphogenesis, Cam­ Gauthier, J. & Padian, K., 1985. "Phylogenetic, bridge: 293-309. Functional, and Aerodynamic Analyses of the

References 188 Mesozoic Meanderings #2 Hinchliffe, J. tL, 1985. " 'One, two, three' or Hunt, A. P. & Lucas, S. G., 1989. "New geno­ 'Two, three, four': An Embryologist's View of type designations for the phytosaurs Mystriosu- the Homologies of the Digits and Carpus of chus and Rutiodon with a discussion of the Modern Birds," in Hecht, Ostrom, Viohl & taxonomic status of Mystriosuchus, Clepsysau- Wellnhofer, eds., 1985:141-147. rus, and Rutiodon," in Lucas & Hunt, eds., 1989: 340-348. Horner, J. IL, 1988. "A new hadrosaur (Reptil- ia: Ornithischia) from the Upper Cretaceous Hunt, A. P. & Lucas, S. G., 1991. "The Paleorhi- Judith River Formation of Montana," Journal nus biochron and the correlation of the non- of Vertebrate Paleontology 8(3): 314-321. marine Upper Triassic of Pangaea," Palaeon­ tology 34(2): 487-501. Horner, J. R-, 1990. "Evidence of diphyletic origination of the hadrosaurian (Reptilia: Or­ Hutt, S., Simmonds, K. & Hullman, G„ 1989. nithischia) dinosaurs," Chapter 13 of Car­ "Predatory dinosaurs from the Isle of Wight," penter & Currie, eds., 1990:179-187. Proceedings of the Isle of Wight Natural His­ tory and Archaeological Society 9: 137-146. Huene, F. von, 1914. "Beitrage zur Geschichte der Archosaurier," Geologische und Palaon- Huxley, T. H., 1868. "On the Animals Which tologische Abhandlungen, N. F., 13: 1-53. Are Most Nearly Intermediate Between the Birds and Reptiles," Annals and Magazine of Huene, F. von, 1923. "Carnivorous Saurischia Natural History 4(2): 66-75. in Europe since the Triassic," Bulletin of the Geological Society of America 34:449—458. Huxley, T. H., 1870. "Further Evidence of the Affinity Between the Dinosaurian Reptiles Huene, F. von, 1926a. "The Carnivorous Sauris­ and Birds," Quarterly Journal of the Geologi­ chia in the Jura and Cretaceous formations cal Society of London 26:12-31. principally in Europe," Revistas Museo de La Plata 29(35): 167 pp. ICZN, 1985. International Code of Zoological Nomenclature, Third Edition, February 1985. Huene, F. von, 1926b. "On several known and London: International Trust for Zoological unknown Reptiles of the Order Saurischia Nomenclature, in association with the British from England and France," Annals and Museum (Natural History): xx + 338 pp. Magazine of Natural History, Series 9, 17: 473- 489. Ivakhnenko, M. F. & Korabelnikov, V. A-, 1987. The Living Past of the Earth: A Book for Huene, F. von, 1932. Die fossile Reptil-Ordnung Students [Zhivoye Proshloye Zemli: Kniga Saurischia, ihre Entwicklung und Geschichte. Dlya Uchashchikhsya], Moscow, "Insight" Monographien zur Geologie und Palaeontolo- Publications: 256 pp. gie, Serie 1, Heft 4, Teile I & II: viii + 361 pp. Ivakhnenko, M. F. & Kurzanov, S. M., 1978. Hulke, J. W., 1881. "Polacanthus Faxii, a large "Mezenosavr—Primitivnii Archosavr [Mesono- undescribed Dinosaur from the Wealden For­ saurus (sic), A Primitive Archosaur]," Paleon- mation in the Isle of Wight," Philosophical tologicheskiy Zhumal 1978(1): 152-155 [in Transactions of the Royal Society of London Russian; English translation in Paleontological 172: 653-^562 + pi. 70-76. Journal 1978(1): 139-141]. Hunt, A. P., 1989. "Cranial morphology and Jensen, J. A, 1985. "Three New Sauropod Di­ ecology among the phytosaurs," in Lucas & nosaurs from the Upper Jurassic of Colora­ Hunt, eds., 1989: 349-354. do," Great Basin Naturalist 45(4): 697-709. Hunt, A. P., 1991. "The early diversification pat­ Kim, H. M., 1983. "Cretaceous Dinosaurs from tern of dinosaurs in the Late Triassic," Korea," Journal of die Geological Society of Modem Geology 16(1/2): 43-60. Korea 19(3): 115-126.

Parainfraclass Archosauria Cope, 1869 189 References Koken, E. von, 1887. "Die Dinosaurier, Croco- London 45: 41-59 & plate II. diliden und Sauropterygier des norddeutsch- Lydekker, R-, 1890a. "Contributions to our en Wealden," Geologische und Palaontologi- Knowledge of the Dinosaurs of the Wealden sche Abhandlungen 3: 309-419. and the Sauropterygians of the Purbeck and Krebs, B., 1976. "Pseudosuchia," in Chang, ," Quarterly Journal of the Geolog­ Krebs, Sues & Westphal, 1976: 40-98. ical Society of London 46: 36-53 & plate V. Kuhn, O., 1939. "Saurischia," Fossilium Cata- Lydekker, 1890b. Catalogue of the Fossil Rep­ logus I: Animalia, Pars 87, W. Quenstedt, ed., tilia and Amphibia in the British Museum, Part Munich: 124 pp. [Reprinted 1972 by W. Junk 4, London, British Museum of Natural His­ and A. Asher & Co., the Netherlands.] tory: 295 pp. Lehman, T. M., 1990. "The ceratopsian subfam­ Madsen, J. H., Jr., 1976. "Allosaurus fragilis: A ily Chasmosaurinae: and Revised Osteology," Utah Geological and Min­ systematics," Chapter 16 of Carpenter & Cur- eral Survey Bulletin 109: xii + 164 pp. rie, eds., 1990: 211-229. Maryanska, T., 1990. "Pachycephalosauria," Levinton, J. S., et aL, 1986 (group report). "Or- Chapter 27 of Weishampel, Dodson & ganismic Evolution: The Interaction of Micro- Osmolska, eds., 1990: 564-577. evolutionary and Macroevolutionary Process­ Marsh, O. C, 1895. "On the Affinities and es," in Raup, D. M. & Jablonski, D., eds., Pat­ Classification of the Dinosaurian Reptiles," terns and Processes in the History of Life, Ber­ American Journal of Science, 3rd Series, 50: lin, Springer-Verlag: 167-182. 483-498. Lucas, S. G. & Hunt, A. P., eds., 1989. Dawn of Martin, L. D„ 1985. "The Relationship of Ar- the Age of Dinosaurs in the American South­ chaeopteryx to other Birds," in Hecht, Os- west, Albuquerque, New Mexico Museum of trom, Viohl & Wellnhofer, eds., 1985: 177- Natural History: iv + 414 pp. + 9 pi. 183. Lull, R. S., 1953. "Triassic Life of the Connecti­ Maryanska, T. & Osmolska, H., 1974. "Pachy­ cut Valley," Connecticut State Geological and cephalosauria, a new suborder of ornithischi- Natural History Survey 81: 336 pp. an dinosaurs," Palaeontologia Polonica 30: 45- Lydekker, R, 1888a. "Note on a new Wealden 102. iguanodont and other dinosaurs," Quarterly Mayr, E., 1942. Systematics and the Origin of Journal of the Geological Society of London Species, New York, Columbia University 44: 46-61. Press: PAGES? Lydekker, R^ 1888b. Catalogue of the Fossil Mcintosh, J. S., 1990. "Sauropoda," Chapter Reptilia and Amphibia in the British Museum, 16 of Weishampel, Dodson & Osmolska, eds., Part 1, Containing the orders Omithosauria, 1990: 345-401. , Dinosauria, , Rhynchoce- phalia, and Proterosauria, London, British Mu­ Milner, A. C. & Croucher, R., 1987. Claws: The seum of Natural History: 309 pp. Story (So Far) of a Great British Dinosaur Baryonyx walkeri, London, British Museum Lydekker, R^ 1889a. "Note on Some Points in (Natural History): 16 pp. + covers. Uie Nomenclature of Fossil Reptiles and Am­ phibians, widi Preliminary Notices of Two Molnar, R. E., 1985. "Alternatives to Archaeop- New Species," Geological Magazine (3rd teryr. A Survey of Proposed Early or Ances­ decade) 6: 325-326. tral Birds," in Hecht, Ostrom, Viohl & Wellnhofer, eds., 1985: 209-217. Lydekker, R^ 1889b. "On the Remains and Af­ finities of five Genera of Mesozoic Reptiles," Quarterly Journal of the Geological Society of

References 190 Mesozoic Meanderings #2 Molnar, R. E., 1990. "Problematic Theropoda: Olsen, P. E. & Galton, P. M., 1984. "A review 'Carnosaurs'," Chapter 14 of Weishampel, of the reptile and amphibian assemblages Dodson & Osm61ska, eds., 1990: 306-317. from the Stormberg of southern Africa, with special emphasis on the footprints and the Molnar, R. E. & Carpenter, K- IL, 1989. "The age of the Stormberg," Paleontologia Africana Jordan Theropod (Maastrichtian, Montana, 25: 87-110. U.S.A.) referred to the genus Aublysodon," Geobios 22(4): 445-454. Olshevsky, G., 1978. "The Archosaurian Taxa (excluding the Crocodylia)," Mesozoic Mean- Molnar, R. E., Kurzanov, S. M. & Dong Z., derings 1: 1-50. 1990. "Camosauria," Chapter 6 of Weisham­ pel, Dodson & Osmblska, eds., 1990: 169-209. Olshevsky, G., 1979. Mesozoic Meanderings #1 Supplement 1 Additions and corrections Nicholls, E. L. & Russell, A. P., 1981. "A new through September 1979: 1-4 (pp. 51-54). specimen of Struthiomimus altus from Alber­ ta, with comments on the classificatory char­ Olshevsky, G., 1980a. Mesozoic Meanderings acters of the Upper Cretaceous ornithomi- #7 Supplement 2 Additions and corrections mids," Canadian Journal of Earth Sciences 18: through October 1980. 55-61. 518-526. Olshevsky, G., 1980b. Mesozoic Meanderings Nopcsa, F., 1915. "Die Dinosaurier der Sieben- #7 Supplement 2A: 1 p. burgischen Landesteile Ungarns," Mitteilun- Olshevsky, G 1991. Dinosaurs from China, gen Jahrbuch konigliche ungarische geologische n book review in Historical Biology 4(A): 343- Reichsanstalt 23: 1-26. 349. Norman, D. B., 1984. "On the cranial morphol­ Olshevsky, G., in preparation a. "Valdoraptor ogy and evolution of ornithopod dinosaurs," oweni (Theropoda: Allosauridae) from the in Ferguson, M. W. J., ed., The Structure, De­ Upper Wealden of West Sussex, England." velopment, and Evolution of Reptiles, Sympo­ Mesozoic Vertebrate Life #2. sium of the Zoological Society of London 52: 521-547. Olshevsky, G., in preparation b. "The Unusual Dorsal Vertebrae of Becklespinax (Therop­ Norman, D. B., 1990. "Problematic Theropoda: oda: Eustreptospondylidae) from the Lower 'Coelurosaurs'," Chapter 13 of Weishampel, Wealden of East Sussex, England," Mesozoic Dodson & Osmdlska, eds., 1990: 280-305. Vertebrate Life #2. Norman, D. B. & Weishampel, D. B„ 1985. "Or­ Osmolska, H. & Barsbold, R., 1990. "Troodon- nithopod feeding mechanisms: Their bearing tidae," Chapter 11 of Weishampel, Dodson & on the evolution of herbivory," American Osm61ska, eds., 1990: 259-268. Naturalist 126:151-164. Ostrom, J. H., 1970. "Stratigraphy and Paleon­ Norman, D. B. & Weishampel, D. B., 1990. tology of the (Lower Cre­ "Iguanodontidae and Related Ornithopods," taceous) of the Bighorn Basin Area, Wyoming Chapter 25 of Weishampel, Dodson & Osm61- and Montana," Peabody Museum of Natural ska, eds., 1990: 510-533. History Bulletin 35: viii + 234 pp. + 27 pi. + Ochev, V. C 1958. "Novye danniye po psevdo- VII charts. zukhiyam SSSR [New data on pseudosuchians Ostrom, J. H., 1976. "Archaeopteryx and the of the USSR]," Doklady Akademii Nauk Origin of Birds," Biological Journal of the Lin- SSSR 123(4): 749-751. naean Society of London 8(2): 91-182. Olsen, P. E., 1979. "A new aquatic eosuchian Ostrom, J. H., 1978. "The osteology of Comp- from the (Late Triassic- sognathus longipes Wagner," Zitteliana 4: 73- Early Jurassic) of North Carolina and Virgin­ 118. ia," Postilla 176: 1-14.

Parainfraclass Archosauria Cope, 1869 191 References Ostrom, J. H., 1980. "The Evidence for Endo- Padian, K., 1984. "The Origin of Pterosaurs," thenny in Dinosaurs," Chapter 1 of Thomas in Reif & Westphal, eds., 1984: 163-168. & Olson, eds., 1980: 15-54. Padian, IC, ed., 1986a. The Origin of Birds and Ostrom, J. H., 1985. "Introduction to Archaeop- the Evolution of Flight, Memoirs of the Califor­ teryx," in Hecht, Ostrom, Viohl & Wellnhof- nia Academy of Sciences 8, San Francisco, er, eds., 1985: 9-20. California Academy of Sciences: viii + 98 pp. Ostrom, J. H., 1990. "Dromaeosauridae," Padian, K-, ed., 1986b. 77ie Beginning of the Chapter 12 of Weishampel, Dodson & Osm61- Age of Dinosaurs: Faunal change across the ska, eds., 1990: 269-279. Triassic-Jurassic boundary, Cambridge Univer­ sity Press: xii + 378 pp. OToole, C, ed^, 1986. The Encyclopedia of In­ sects, New York, Facts On File Publications: Padian, K. & Clemens, W. A^ 1985. "Terrestri­ 144 + XVI pp. al Vertebrate Diversity: Episodes and In­ sights," Chapter 2 in J. W. Valentine, ed., Otte, D. & Endler, J. A-, eds., 1989. Speciation Phanerozoic Diversity Patterns: Profiles in Mac- and Its Consequences, Sunderland, Massachu­ roevolution, Princeton University Press: 41-96. setts, Sinauer Associates, Inc.: xiii + 679 pp. Parrisli, J. M., 1986. "Locomotor adaptations Owen, R-, 1842. "Report on British Fossil Rep­ in the hindlimb and pelvis of the Thecodon- tiles, Part II," Report of the British Association tia," Hunteria 1: 1-35. for the Advancement of Science, 11th Meeting, Plymouth: 60-204. Paul, G. S., 1984. "The Archosaurs: A Phyloge- netic Study," in Reif & Westphal, eds., 1984: Owen, R, 1855. Monograph on the Fossil Reptil- 175-180. ia of the Wealden and Purbeck Formations. Part II. Dinosauria (Iguanodon). (Wealden). Paul, G. S., 1988a. "The Brachiosaur Giants of Palaeontographical Society, London 8: 54 pp. the Morrison and Tendaguru with a Descrip­ + XIX pi. tion of a New Subgenus, Giraffatitan, and a Comparison of the World's Largest Dino­ Owen, IL, 1856. Monograph on the Fossil Rep- saurs," Hunteria 2(3): 1-14. tilia of the Wealden Formations. Part III. Meg- alosaurus bucklandi. Palaeontographical Soci­ Paul, G. S., 1988b. Predatory Dinosaurs of the ety, London 9(34): 26 pp. + XII pi. [Reprint­ World. New York, Simon & Schuster: 464 pp. ed by the Johnson Reprint Corp., New York, Peters, D. S. & Gutmann, W. F., 1985. "Con­ 1966.] structional and Functional Preconditions for Owen, It, 1857. Monograph on the Fossil Rep- the Transition to Powered Flight in Verte­ tilia of the Wealden Formation. Part IV. Palae­ brates," in Hecht, Ostrom, Viohl & Wellnhof- ontographical Society, London 10(43): 26 pp. er, eds., 1985: 233-242. + XI pi. [Reprinted by the Johnson Reprint Perle, A, Maryanska, T. & Osmolska, H., Corp., New York, 1966.] 1982. "Goyocephale lattimorei gen. et sp. nov., Padian, IC, 1983a. "Osteology and functionl a new flat-headed pachycephalosaur (Orni- morphology of Dimorphodon macronyx (Buck- thischia, Dinosauria) from the Upper Creta­ land) (Pterosauria: ) ceous of Mongolia," Acta Palaeontologia Po- based on new material in the Yale Peabody lonica 27:115-127. Museum," Postilla 189: 1-44. Rayner, J. M. V., 1985a. "Mechanical and Eco­ Padian, IL, 1983b. "A functional analysis of fly­ logical Constraints on Flight Evolution," in ing and walking in pterosaurs," Paleobiology Hecht, Ostrom, Viohl & Wellnhofer, eds., 9(3): 218-239. 1985: 279-288.

References 192 Mesozoic Meanderings #2 Rayner, J. M. V., 1985b. "Cursorial Gliding in from the Middle Triassic of Spain," Geobios Proto-Birds: An Expanded Version of a Dis­ 17(6): 747-753 + 1 pi. cussion Contribution," in Hecht, Ostrom, Schoch, R. M., 1986. Phytogeny Reconstruction Viohl & Wellnhofer, eds., 1985: 289-292. in Paleontology, New York, Van Nostrand Regal, P. J. & Gans, C„ 1980. "The Revolution Reinhold: xii + 353 pp. in Thermal Physiology," Chapter 6 of Thomas Seeley, H. G., 1888. "On the Classification of & Olson, eds., 1980: 167-188. the Fossil Animals Commonly Named Dino- Reif, W.-E. & Westphal, F., eds., 1984. Third sauria," Proceedings of the Royal Society of Symposium on Mesozoic Terrestrial Ecosys­ London 43:165-171. tems, Tubingen, Attempto Verlag: PAGES? Sennikov, A. GM 1988. "RoP drevneishikh teko- Reig, O. A, 1961. "Acerca de la Position Siste- dontov v kompleksakh pozvonochnikh vos- mdtica de la Familia Rauisuchidae y del Gen- tochnoi Evropy [The role of the earliest theco- ero Saurosuchos (Reptilia, Thecodontia)," dontians in vertebrate complexes of eastern Publicaciones del Museo Municipal de Cienci- Europe]," Paleontologicheskiy Zhumal as Naturales y Tradicionales de Mar del Plata 1988(4): 18-87 [in Russian]. 7(3): 73-114. Sennikov, A. G., 1989. "Osnovniye evolutsionni- Reynolds, S. rL, 1939. "On a Collection of Rep­ ye zakonomernosti razvitiya lokomotornovo tilian Bones from the Oolite of Stow-on- apparata arkhozavrov [Basic evolutionary Wold, Gloucestershire," The Geological Maga­ laws of development of the locomotor appa­ zine 76(5): 193-214. ratus in the archosaurs]," Paleontologicheskiy Zhumal 1989(A): 63-72 [in Russian; English Ross, C. A. & Garnett, S-, eds., 1989. Croco­ translation in Paleontological Journal 1989(4): diles and Alligators, New York, Facts On File 60-68]. Publications: 240 pp. Sennikov, A. G., 1990. "Noviye danniye po raui- Rowe, T. & Gauthier, J„ 1990. "Ceratosauria," zukhidam Vostochnoi Yevropy [New data on Chapter 5 of Weishampel, Dodson & Osm61- the rauisuchids of eastern Europe]," Paleonto­ ska, eds., 1990:151-168. logicheskiy Zhumal 1990(3): 3-16 [in Russian; Russell, D. A_, 1970. "Tyrannosaurs from the English translation in Paleontological Journal Late Cretaceous of Western Canada," Nation­ 1990(3): 1-12]. al Museums of Canada Publications in Paleon­ Sereno, P. C, 1984. "The Phylogeny of the Or- tology 1: viii + 34 pp. nithischia: A Reappraisal," in Reif & Russell, D. A, 1972. "Ostrich dinosaurs from Westphal, eds., 1984: 219-226. the Late Cretaceous of western Canada," Ca­ Sereno, P. C, 1986. "Phylogeny of the Bird- nadian Journal of Earth Sciences 9: 375-402. hipped Dinosaurs (Order Ornithischia)," Na­ Santa Luca, A. P., 1980. "The postcranial skele­ tional Geographic Research 2(2): 234-256. ton of Heterodontosaurus tucki (Reptilia, Orni- Sereno, P. C, 1990. "Psittacosauridae," Chap­ thischia) from the Stormberg of South Afri­ ter 28 of Weishampel, Dodson & Osmolska, ca," Annals of the South African Museum 79: eds., 1990: 579-592. 159-211. Sereno, P. G, 1991. "Lesothosaurus, 'Fabrosau- Sanz, J. L*, 1990. "Adaptation al vuelo," in Di- rids,' and the Early Evolution of Ornithis­ nosaurios, Madrid, Museo National de Cienti- chia," Journal of Vertebrate Paleontology as Naturales: 82-95. 11(2): 168-197. Sanz, J. L. & Lopez-Martfnez, N., 1984. "The Sharov, A. G., 1970. "Svoyeobraznaya reptiliya prolacertid lepidosaurian Cosesaurus aviceps iz nizhnevo triasa Fergany [An unusual reptile Ellenberger & Villalta, a claimed 'protoavian' from the Lower Triassic of Fergana]," Pa-

Parairtfraclass Archosauria Cope, 1869 193 References leontologicheskiy Zhumal 1970(1): 127-130 [in ogyj 16, O. Kuhn, ed. Stuttgart, Gustav Fisch­ Russian; English translation in Paleontologi- er Verlag: 116 pp. cat Journal 1970(1): 112-116]. Stovall, J. W. & Langston, W., 1950. "Acrocan- Sharov, A. G., 1971. "[New flying reptiles from thosaurus atokensis, a New Genus and Spe­ the Mesozoic deposits of Kazakhstan and Kir­ cies of Lower Cretaceous Theropoda from ghizia]," Transactions of the Paleontological Oklahoma," American Midland Naturalist Institute of the USSR Academy of Sciences 43(3): 696-728. 130: 104-113 [in Russian]. Stronier, E., 1915. "Ergebnisse der Forschungs- Sibley, C. G. & Ahlquist, J. E., 1990. Phytogeny reisen Prof. E. Stromers in den Wiisten Agyp- and Classification of Birds: A Study in Molecu­ tens. II. Wirbeltier-Reste der Baharije-Stufe lar Evolution, New Haven, (unterstes Cenoman). 3. Das Original des Press: xxiv + 976 pp. Theropoden Spinosaurus aegyptiacus," Ab- handlungen der koniglichen Bayerischen Akade- Sibley, C. G. & Monroe, B. I~, Jr., 1990. Distri­ mie der Wissenschaften 28(3): 1-32. bution and Taxonomy of Birds of the World, New Haven, Yale University Press: xxiv + Sues, H.-D., 1976. "Thecodontia incertae sedis: 1111 pp. Proterochampsidae," in Charig, Krebs, Sues & Westphal, 1976: 121-126. Sill, W. D., 1967. "Proterochampsa barrioneuvoi and the Early Evolution of the Crocodilia," Sues, H.-D., 1989. "The Place of Crocodilians Bulletin of the Museum of Comparative Zool­ in the Living World," in Ross & Garnett, ogy 135(8): 415-446. eds., 1989: 14-25. Sill, W. D., 1974. "The Anatomy of Saurosu- Sues, H.-D., 1990. "Staurikosaurus and Herrera- chus galilei and the Relationships of the Raui- sauridae," Chapter 4 of Weishampel, Dodson suchid Thecodonts," Bulletin of the Museum & Osm61ska, eds., 1990: 143-147. of Comparative Zoology 146(7): 317-362. Sues, H.-D. & Norman, D. B., 1990. "Hypsilo- Smith, D. & Gallon, P. M., 1990. "Osteology of phodontidae, Tenontosaurus, Dryosauridae," Archaeomithomimus asiaticus (Upper Creta­ Chapter 24 of Weishampel, Dodson & Osmol- ceous, Iren Dabasu Formation, People's Re­ ska, eds., 1990: 498-509. public of China)," Journal of Vertebrate Pale­ Swinton, W. E., 1936. "The Dinosaurs of the ontology 10(2): 255-265. Isle of Wight," Proceedings of the Geological Stanley, S. M., 1973. "An Explanation for Association 47(3): 204-220. Cope's Law," Evolution 27: 1-26. Tarsiitano, S. & Hecht, M. FC, 1980. "A recon­ Stanley, S. Mn 1987. Extinction, New York, sideration of the reptilian relationships of Ar- W. H. Freeman & Co., Scientific American chaeopteryx," Zoological Journal of the Linnae- Library: xii + 242 pp. an Society of London 69(2): 149-182. Steel, R^ 1969. "Ornithischia," Handbuch der Thomas, R. D. K. & Olson, E. C, eds., 1980. A Palaoherpetologie [Encyclopedia of Paleoher- Cold Look at the Warm-Blooded Dinosaurs, petology] 15, O. Kuhn, ed., Stuttgart, Gustav AAAS Selected Symposium 28, Boulder, Co­ Fischer Verlag. lorado, Westview Press: xxx + 514 pp. Steel, R^ 1970. "Saurischia," Handbuch der Pa­ Thulborn, R. A^ 1979. "A proterosuchian the­ laoherpetologie [Encyclopedia of Paleoherpetol- codont from the Rewan Formation of Queens­ ogyj 14, O. Kuhn, ed., Stuttgart, Gustav Fisch­ land," Memoirs of the Queensland Museum er Verlag: 87 pp. 19(3): 331-355. Steel, R^ 1973. "Crocodylia," Handbuch der Pa­ Thulborn, R. A^ 1984. "The avian relationships laoherpetologie [Encyclopedia of Paleoherpetol- of Archaeopteryx, and the origin of birds," Zo-

References 194 Mesozoic Meanderings #2 ological Journal of the Linnean Society 82: 119- Weishampel. D. B. & Witmer, L. M., 1990a. 158. "Lesothosaurus, Pisanosaurus, and Technosau- Thulborn, R. A-, 1990. Dinosaur Tracks, Lon­ rus," Chapter 19 of Weishampel, Dodson & don, Chapman and Hail: xviii + 410 pp. Osm61ska, eds., 1990: 416-425. Weishampel, D. B. & Witmer, L. M., 1990b. Thulborn, R. A. & Hamley, T. I*, 1982. "The "Heterodontosauridae," Chapter 23 of Weis­ Reptilian Relationships of Archaeopteryx," hampel, Dodson & Osmolska, eds., 1990: 486- Australian Journal of Zoology 30: 611-634. 497. Tucker, B. W., 1938. "Some observations on Wellnhofer, P., 1988. "Terrestrial locomotion in Dr. Lowe's theory of the relationship of the pterosaurs," Historical Biology 7(1): 3-16. struthiones to the dinosaurs and to other birds," Proceedings of the 8th International Or­ Wellnhofer, P., 1991. Tl\e Illustrated Encyclope­ nithological Conference, Oxford, 1934: 222-224. dia of Pterosaurs, New York, Crescent Books: 192 pp. Unwin, D. M., 1987. "Pterosaur locomotion: Joggers or waddlers?" Nature 327:13-14. Westphal, F., 1976. "Phytosauria," in Chang, Krebs, Sues & Westphal, 1976: 99-120. Unwin, D. M., 1988. "New remains of the ptero­ saur Dimorphodon (Pterosauria: Rhampho- White, T. E., 1973. "Catalogue of the Genera of rhynchoidea) and the terrestrial ability of ear­ Dinosaurs," Annals of Carnegie Museum 44 ly pterosaurs," Modem Geology 13: 57-68. (Article 99): 117-155. Walker, A. D., 1964. "Triassic Reptiles from Young C. C, 1958. "The dinosaurian remains the Elgin area: Omithosuchus and the origin of Laiyang, Shantung," Palaeontologia Sinica of Carnosaurs," Philosophical Transactions of Series C 16: 1-138 [in Chinese and English]. the Royal Society of London Series B 248 (744): 53-134. Young C C, 1973. "On a new pseudosuchian from Turfan, Sinkiang," Reports on the Paleon- Walker, A. D., 1970. "A revision of the Jurassic tological Expedition from Sinkiang I: Memoirs Hallopus victor (Marsh), with remarks on the of the Institute of Vertebrate Paleontology and classification of ," Philosophical Paleoanthropology, Academia Sinica 10: 15-37 Transactions of the Royal Society of London + 2 pi. [in Chinese]. Series B 257: 323-372. Young C. C. & Dong Z., 1972. "Aquatic rep­ Wang FL, 1959. "Ueber eine nue fossile Reptil- tiles from Triassic of China," Memoirs of the form von Provinz Hupeh, China," Acta Palae- Institute of Vertebrate Paleontology and Paleo- ontologia Sinica 7: 367-378. anthropology, Academia Sinica 9: 1-34 + pi. I-XIII [in Chinese]. Weems, R. E^ 1980. "An Unusual Newly Dis­ covered Archosaur From the Upper Triassic Zhang F., 1975. "A new thecodont Lotosaurus, of Virginia, U.S A.," Transactions of the Amer­ from Middle Triassic of Hunan," Vertebrata ican Philosophical Society 70(7): 1-53. PalAsiatica 73(3): 144-147 + plate I. Weishampel, D. B., 1990. "Thyreophora," in Zhang Y., 1988. 77te Middle Jurassic Dinosaur Weishampel, Dodson & OsnuMska, eds., 1990: Fauna from Dashanpu, Zigong, , Vol­ 426. ume III, Sauropod Dinosaurs (I), Shunosau- rus. Chengdu, China, Sichuan Publishing Weishampel, D. B., Dodson, P. & Osmolska, House of Science and Technology: XV pi. + H., eds., 1990. The Dinosauria, Berkeley, Uni­ [vii] + 89 pp. [in Chinese with English ab­ versity of California Press: xvi + 733 pp. stract and figure captions.] Weishampel, D. B. & Horner, J. R-, 1990. "Hadrosauridae," Chapter 26 of Weishampel, Dodson & Osmdlska, eds., 1990: 534-561.

Parainf raclass Archosauria Cope, 1869 195 References Zittel, K. A^ 1887-90. Handbuch der Palaeonto- and Leipzig, R. Oldenbourg: XII + 900 pp. lope. Abteilung 1: Palaeozoologie, 3. Munich

References 196 Mesozoic Meanderings #2