DOCSLIB.ORG

Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha) Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha) by Richard Kissel A thesis submitted in conformity with the requirements for the degree of doctor of philosophy Graduate Department of Ecology & Evolutionary Biology University of Toronto © Copyright by Richard Kissel 2010 Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha) Richard Kissel Doctor of Philosophy Graduate Department of Ecology & Evolutionary Biology University of Toronto 2010 Abstract Based on dental, cranial, and postcranial anatomy, members of the Permo-Carboniferous clade Diadectidae are generally regarded as the earliest tetrapods capable of processing high-fiber plant material; presented here is a review of diadectid morphology, phylogeny, taxonomy, and paleozoogeography. Phylogenetic analyses support the monophyly of Diadectidae within Diadectomorpha, the sister-group to Amniota, with Limnoscelis as the sister-taxon to Tseajaia + Diadectidae. Analysis of diadectid interrelationships of all known taxa for which adequate specimens and information are known—the first of its kind conducted—positions Ambedus pusillus as the sister-taxon to all other forms, with Diadectes sanmiguelensis, Orobates pabsti, Desmatodon hesperis, Diadectes absitus, and (Diadectes sideropelicus + Diadectes tenuitectes + Diasparactus zenos) representing progressively more derived taxa in a series of nested clades. In light of these results, it is recommended herein that the species Diadectes sanmiguelensis be referred to the new genus Oradectes, Diadectes absitus be referred to the new genus Silvadectes, and Diasparactus be synonymized with Diadectes to produce Diadectes zenos. The phylogenetic hypothesis also reveals an evolutionary history leading to more efficient oral processing within the lineage, with successive nodes characterized by features indicative of a high-fiber diet. Within Diadectomorpha, diadectids constitute the majority of the species, ii suggesting that the advent of herbivory resulted in a relatively rapid radiation of species within the group, producing a clade that is markedly more species-rich than other, non-herbivorous diadectomorph taxa. An extensive review of Permo-Carboniferous tetrapod-bearing localities does, however, indicate that diadectids were not a key component of the fauna, discovered at fewer than 50 percent of the sites reviewed. These results counter suggestions that the evolution of Diadectidae led to the formation of the modern terrestrial ecosystem—where a large crop of herbivores supports a much smaller number of carnivores—during the Late Carboniferous and Early Permian. iii Acknowledgments I would like to thank my thesis committee chairperson, Dr. Robert Reisz, for his guidance, encouragement, and continued support of this project and my career. Words simply cannot express the gratitude that I will forever hold. I also wish to extend thanks to the members of my final exam committee, Drs. David Evans, Hans-Dieter Sues, Denis Walsh, and Rick Winterbottom. For her patience, teaching, and continual smile, a special thanks is offered to Ms. Diane Scott. For the loan of specimens critical to this study, I thank: Bill Amaral and Charles Schaff (Museum of Comparative Anatomy, Cambridge); Victoria Byre and Jeff Person (Sam Noble Oklahoma Museum of Natural History, Norman); Greg Gunnell (Museum of Paleontology, Ann Arbor); Brian Iwama and Kevin Seymour (Royal Ontario Museum, Toronto); Amy Henrici (Carnegie Museum of Natural History, Pittsburgh); and William Simpson (Field Museum of Natural History, Chicago). And for many discussions of diadectid anatomy, I thank Dr. David Berman of the Carnegie Museum. Finally, I thank those beautiful few that have have offered their love and support throughout not only this study but throughout my life. Thank you. iv Table of Contents Abstract ii Acknowledgments iv List of Tables viii List of Figures ix List of Appendices xv Chapter 1 Introduction and Historical Background 1 Chapter 2 Description of a New Diadected from the Lower Permian of Ohio 6 1 Introduction 6 2 Description and Comparison 8 2.1 Introduction 8 2.2 Maxilla 9 2.3 Dentary 14 2.4 Ambedus pusillus and diadectid ontogeny 18 2.5 Conclusions 19 Chapter 3 Phylogeny of Diadectidae 25 3 Introduction 25 4 Excluded Taxa 26 5 Monophyly of Diadectidae 29 5.1 Revisiting Diadectomorpha as the sister-taxon to Amniota 32 v 6 Interrelationships of Diadectidae 35 6.1 Taxonomic Implications 39 7 Conclusions 42 Chapter 4 Systematic Revision 69 8 Diadectidae Cope 1880a 69 8.1 Ambedus Kissel and Reisz 2004, p. 198 70 8.2 Orobates Berman et al. 2004, p. 3 71 8.3 Oradectes n. gen. 72 8.4 Desmatodon Case, 1908, p. 236 74 8.5 Silvadectes n. gen. 76 8.6 Diadectes Cope 1878a, p. 505 78 8.7 Problematic Taxa Assigned to Diadectidae 82 Chapter 5 Evolution of Diadectidae 91 9 Introduction 91 10 Evolutionary Radiation of Diadectidae 92 11 Evolutionary Trends within Diadectidae 94 Chapter 6 Stratigraphic and Geographic Distribution of P-C Tetrapods 99 12 Introduction 99 13 Permo-Carboniferous Tetrapod-bearing Localities 101 13.1 Missourian 102 vi 13.2 Virgilian 106 13.3 Wolfcampian 113 13.4 Leonardian 127 14 Results and Conclusions 143 References 156 Appendix 1 169 Appendix 2 173 Appendix 3 177 Appendix 4 181 vii List of Tables Table 1. Maximum crown measurements (in mm) and ratios of largest preserved, midseries maxillary cheek teeth in selected specimens of Diadectes, Desmatodon, Orobates, and Ambedus. Modified from Berman and Sumida (1995). Table 2. Maximum crown measurements (in mm) and ratios of largest preserved, midseries dentary cheek teeth in selected specimens of Diadedectes, Diasparactus, Desmatodon, Orobates, and Ambedus. Modified from Berman and Sumida (1995) and Kissel and Lehman (2002). Table 3. Missourian locality data, listing those tetrapod-bearing sites that produce taxa thought to possess an herbivorous diet. Table 4. Virgilian locality data, listing those tetrapod-bearing sites that produce taxa thought to possess an herbivorous diet. Table 5. Wolfcampian locality data, listing those tetrapod-bearing sites that produce taxa thought to possess an herbivorous diet. Table 6. Leonardian locality data, listing those tetrapod-bearing sites that produce taxa thought to possess an herbivorous diet. viii List of Figures Fig. 1. MCZ 9436, right maxilla and holotype of Ambedus pusillus in lateral (A), occlusal (B), and medial (C) views. Numbers indicate tooth positions. From Kissel and Reisz (2004a). Scale = 1 cm. Fig. 2. Fifth posteriormost maxillary tooth of MCZ 9436 (A) and fifth posteriormost dentary tooth of MCZ 9440 (B) in posterior view. From Kissel and Reisz (2004a). Scale = 1 cm. Fig. 3. MCZ 9438, complete left dentary of Ambedus pusillus in lateral view. Numbers indicate tooth positions. From Kissel and Reisz (2004a). Scale = 1 cm. Fig. 4. MCZ 9439, right dentary of Ambedus pusillus in lateral (A) and medial (B) views. Numbers indicate tooth positions. From Kissel and Reisz (2004a). Scale = 1 cm. Fig. 5. MCZ 9440, left dentary of Ambedus pusillus in lateral (A) and occlusal (B) views. Numbers indicate tooth positions. From Kissel and Reisz (2004a). Scale = 1 cm. Fig. 6. OMNH 56871, articulated left frontal and postfrontal in dorsal view (A), OMNH 56872a (B) and OMNH 56873 (C), premaxillary incisor teeth in lingual and lateral views, and OMNH 56875 (D) and OMNH 56872b (E) in probable posterior, anterior, and lingual views. From Reisz and Sutherland (2001). Scale = 1 cm. Fig. 7. Articulated series of four presacral and two sacral vertebrae of Phanerosaurus naumanni, the sole specimen assigned to the form, in left lateral (top) and dorsal (bottom) views. From Meyer (1860; no scale provided). Fig. 8. Partial left lower jaw in medial view (A), partial right dentary in medial view (B), right maxilla in lateral view (C), and vertebrae (D) of Stephanospondylus pugnax; MNG 14000, a partial skull of Orobates pabsti in lateral view (E). B from Stappenbeck (1905; no scale provided); C-D from Geinitz and Deichmüller (1882; no scale provided); scale for E = 1 cm. Fig. 9. Hypothesis demonstrating the monophyly of Diadectomorpha and Diadectidae. Autapomorphies of the clades and terminal taxa are as follows, with all characters listed possessing an unambiguous history: Node A (Cotylosauria): 5(1), 33(1), 35(1); Amniota: 1(1), ix 11(1), 24(1); Node B (Diadectomorpha): 2(1), 4(1), 18(1), 25(1), 26(1), 32(1), 36(1), 37(1); Node C: 3(1), 8(1); Node D (Diadectidae): 27(1), 30(1), 31(1); Node E: 22(1), 26(2), 28(1); Node F: 12(1); 20(1); Node G: 19(1), 22(2), 30(2), 31(2). Bootstrap and decay index values determined in Paup 4.0b10 are: Node B: 97, 4; Node C: 56, 1; Node D: 96, 3; Node E: 95, 3; Node F: 95, 3; Node G: 92, 3. Fig. 10. CM 1938, holotype and only known specimen (a partial left maxilla) of Desmatodon hollandi in lateral (A), medial (B), and occlusal (C) views. Scale = 1 cm. Fig. 11. Skull (palatal view; A) and right lower jaw of Diadectes lentus in occlusal (B), medial (C), and lateral (D) views. Scale = 1 cm. Ang, angular; s.ang, surangular; art, articular; p.art, prearticular; d, dentary; spl, splenial; ant fenestra, anterior fenestra; med fenestra, medial fenestra; post fenestra, posterior fenestra; numbers indicate tooth positions. A and B from Case and Williston (1912); C-E from Welles (1941). Fig. 12. YPM 817, partial skull of Diadectes carinatus in palatal view. From Case and Williston (1912). Scale = 1 cm. Fig. 13. Skull reconstruction of Limnoscelis paludis is dorsal (A), ventral (B), lateral (C), and occipital (D) views, as well as the lateral (E) and medial (F) views of the lower jaw, based on holotype YPM 811. Scale = 2 cm. a, angular; ac, anterior coronoid; ar, articular; bo, basioccipital; d, dentary; ec, ectopterygoid; f, frontal; j, jugal; l, lacrimal; m, maxilla; n, nasal; op, opisthotic; p, parietal; pc, posterior coronoid; pf, postfrontal; pl, palatine; pm, premaxilla; po, postorbital; pp, postparietal; pra, prearticular; prf, prefrontal; ps, parasphenoid; pt, pterygoid; q, quadrate; qj, quadratojugal; s, septomaxilla; sa, surangular; so, supraoccipital; sp, splenial; sq, squamosal; st, supratemporal; t, tabular; v, vomer.
Load more

Recommended publications
  • Identifying Heterogeneity in Rates of Morphological Evolution: Discrete Character Change in the Evolution of Lungfish (Sarcopterygii; Dipnoi)
    ORIGINAL ARTICLE doi:10.1111/j.1558-5646.2011.01460.x IDENTIFYING HETEROGENEITY IN RATES OF MORPHOLOGICAL EVOLUTION: DISCRETE CHARACTER CHANGE IN THE EVOLUTION OF LUNGFISH (SARCOPTERYGII; DIPNOI) Graeme T. Lloyd,1,2 Steve C. Wang,3 and Stephen L. Brusatte4,5 1Department of Palaeontology, Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom 2E-mail: [email protected] 3Department of Mathematics and Statistics, Swarthmore College, Swarthmore, Pennsylvania 19081 4Division of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024 5Department of Earth and Environmental Sciences, Columbia University, New York, New York 10025 Received February 9, 2010 Accepted August 15, 2011 Data Archived: Dryad: doi:10.5061/dryad.pg46f Quantifying rates of morphological evolution is important in many macroevolutionary studies, and critical when assessing possible adaptive radiations and episodes of punctuated equilibrium in the fossil record. However, studies of morphological rates of change have lagged behind those on taxonomic diversification, and most authors have focused on continuous characters and quantifying patterns of morphological rates over time. Here, we provide a phylogenetic approach, using discrete characters and three statistical tests to determine points on a cladogram (branches or entire clades) that are characterized by significantly high or low rates of change. These methods include a randomization approach that identifies branches with significantly high rates and likelihood ratio tests that pinpoint either branches or clades that have significantly higher or lower rates than the pooled rate of the remainder of the tree. As a test case for these methods, we analyze a discrete character dataset of lungfish, which have long been regarded as “living fossils” due to an apparent slowdown in rates since the Devonian.
    [Show full text]
  • Reptile Family Tree
    Reptile Family Tree - Peters 2015 Distribution of Scales, Scutes, Hair and Feathers Fish scales 100 Ichthyostega Eldeceeon 1990.7.1 Pederpes 91 Eldeceeon holotype Gephyrostegus watsoni Eryops 67 Solenodonsaurus 87 Proterogyrinus 85 100 Chroniosaurus Eoherpeton 94 72 Chroniosaurus PIN3585/124 98 Seymouria Chroniosuchus Kotlassia 58 94 Westlothiana Casineria Utegenia 84 Brouffia 95 78 Amphibamus 71 93 77 Coelostegus Cacops Paleothyris Adelospondylus 91 78 82 99 Hylonomus 100 Brachydectes Protorothyris MCZ1532 Eocaecilia 95 91 Protorothyris CM 8617 77 95 Doleserpeton 98 Gerobatrachus Protorothyris MCZ 2149 Rana 86 52 Microbrachis 92 Elliotsmithia Pantylus 93 Apsisaurus 83 92 Anthracodromeus 84 85 Aerosaurus 95 85 Utaherpeton 82 Varanodon 95 Tuditanus 91 98 61 90 Eoserpeton Varanops Diplocaulus Varanosaurus FMNH PR 1760 88 100 Sauropleura Varanosaurus BSPHM 1901 XV20 78 Ptyonius 98 89 Archaeothyris Scincosaurus 77 84 Ophiacodon 95 Micraroter 79 98 Batropetes Rhynchonkos Cutleria 59 Nikkasaurus 95 54 Biarmosuchus Silvanerpeton 72 Titanophoneus Gephyrostegeus bohemicus 96 Procynosuchus 68 100 Megazostrodon Mammal 88 Homo sapiens 100 66 Stenocybus hair 91 94 IVPP V18117 69 Galechirus 69 97 62 Suminia Niaftasuchus 65 Microurania 98 Urumqia 91 Bruktererpeton 65 IVPP V 18120 85 Venjukovia 98 100 Thuringothyris MNG 7729 Thuringothyris MNG 10183 100 Eodicynodon Dicynodon 91 Cephalerpeton 54 Reiszorhinus Haptodus 62 Concordia KUVP 8702a 95 59 Ianthasaurus 87 87 Concordia KUVP 96/95 85 Edaphosaurus Romeria primus 87 Glaucosaurus Romeria texana Secodontosaurus
    [Show full text]
  • Wann Langston, Jr. – a Life Amongst Bones Christopher J
    Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 103, 189–204, 2013 (for 2012) Wann Langston, Jr. – a life amongst bones Christopher J. Bell1, Matthew A. Brown,2, 4 Mary R. Dawson3 and Ernest L. Lundelius, Jr2 1 Department of Geological Sciences, The University of Texas at Austin, Austin, TX 78712, USA Email: [email protected] 2 Vertebrate Paleontology Laboratory, University of Texas at Austin, 10100 Burnet Rd, R7600, Austin, TX 78758, USA Emails: [email protected]; [email protected] 3 Carnegie Museum of Natural History, 4400 Forbes Avenue, Pittsburgh, PA 15213–4080, USA Email: [email protected] 4 School of Museum Studies, University of Leicester, Museum Studies Building, 19 University Road, Leicester LE1 7RF, UK Wann Langston Jr. was born on 10 July, 1921 in Oklahoma another nurse, Clara Louise Jones. Wann was, thus, raised in City, Oklahoma. He was the only surviving son of Wann a family in which higher education, and specifically medical Langston and Myrtle Fanning Langston, who died in child- and anatomical training, was common to both parents. Clara’s birth as his life began. Three previous children all died young. father was the headmaster of Salado College and was a Regent The derivation of the name ‘‘Wann’’ is not fully known, but of The University of Texas, where Wann later spent much of his appears to have been the patronymic of an itinerant, African- professional career as a palaeontologist. Clara was a gifted American Baptist preacher who visited Wann’s grandfather linguist, with an especial passion for Greek (although she did and made a sufficiently strong impression that he named his not know the word ‘palaeontologist’; Wann remembers her son Wann.
    [Show full text]
  • The Lower Permian Abo Formation in the Fra Cristobal and Caballo Mountains, Sierra County, New Mexico Spencer G
    New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/63 The Lower Permian Abo Formation in the Fra Cristobal and Caballo Mountains, Sierra County, New Mexico Spencer G. Lucas, Karl Krainer, Dan S. Chaney, William A. DiMichele, Sebastian Voigt, David S. Berman, and Amy C. Henrici, 2012, pp. 345-376 in: Geology of the Warm Springs Region, Lucas, Spencer G.; McLemore, Virginia T.; Lueth, Virgil W.; Spielmann, Justin A.; Krainer, Karl, New Mexico Geological Society 63rd Annual Fall Field Conference Guidebook, 580 p. This is one of many related papers that were included in the 2012 NMGS Fall Field Conference Guidebook. Annual NMGS Fall Field Conference Guidebooks Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. These books have set the national standard for geologic guidebooks and are an essential geologic reference for anyone working in or around New Mexico. Free Downloads NMGS has decided to make peer-reviewed papers from our Fall Field Conference guidebooks available for free download. Non-members will have access to guidebook papers two years after publication. Members have access to all papers. This is in keeping with our mission of promoting interest, research, and cooperation regarding geology in New Mexico. However, guidebook sales represent a significant proportion of our operating budget. Therefore, only research papers are available for download.
    [Show full text]
  • Distributions of Extinction Times from Fossil Ages and Tree Topologies: the Example of Some Mid-Permian Synapsid Extinctions
    bioRxiv preprint doi: https://doi.org/10.1101/2021.06.11.448028; this version posted June 11, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Distributions of extinction times from fossil ages and tree topologies: the example of some mid-Permian synapsid extinctions Gilles Didier1 and Michel Laurin2 1IMAG, Univ Montpellier, CNRS, Montpellier, France 2CR2P (“Centre de Recherches sur la Paléobiodiversité et les Paléoenvironnements”; UMR 7207), CNRS/MNHN/UPMC, Sorbonne Université, Muséum National d’Histoire Naturelle, Paris, France June 11, 2021 Abstract Given a phylogenetic tree of extinct and extant taxa with fossils where the only temporal infor- mation stands in the fossil ages, we devise a method to compute the distribution of the extinction time of a given set of taxa under the Fossilized-Birth-Death model. Our approach differs from the previous ones in that it takes into account the possibility that the taxa or the clade considered may diversify before going extinct, whilst previous methods just rely on the fossil recovery rate to estimate confidence intervals. We assess and compare our new approach with a standard previous one using simulated data. Results show that our method provides more accurate confidence intervals. This new approach is applied to the study of the extinction time of three Permo-Carboniferous synapsid taxa (Ophiacodontidae, Edaphosauridae, and Sphenacodontidae) that are thought to have disappeared toward the end of the Cisuralian, or possibly shortly thereafter. The timing of extinctions of these three taxa and of their component lineages supports the idea that a biological crisis occurred in the late Kungurian/early Roadian.
    [Show full text]
  • 71St Annual Meeting Society of Vertebrate Paleontology Paris Las Vegas Las Vegas, Nevada, USA November 2 – 5, 2011 SESSION CONCURRENT SESSION CONCURRENT
    ISSN 1937-2809 online Journal of Supplement to the November 2011 Vertebrate Paleontology Vertebrate Society of Vertebrate Paleontology Society of Vertebrate 71st Annual Meeting Paleontology Society of Vertebrate Las Vegas Paris Nevada, USA Las Vegas, November 2 – 5, 2011 Program and Abstracts Society of Vertebrate Paleontology 71st Annual Meeting Program and Abstracts COMMITTEE MEETING ROOM POSTER SESSION/ CONCURRENT CONCURRENT SESSION EXHIBITS SESSION COMMITTEE MEETING ROOMS AUCTION EVENT REGISTRATION, CONCURRENT MERCHANDISE SESSION LOUNGE, EDUCATION & OUTREACH SPEAKER READY COMMITTEE MEETING POSTER SESSION ROOM ROOM SOCIETY OF VERTEBRATE PALEONTOLOGY ABSTRACTS OF PAPERS SEVENTY-FIRST ANNUAL MEETING PARIS LAS VEGAS HOTEL LAS VEGAS, NV, USA NOVEMBER 2–5, 2011 HOST COMMITTEE Stephen Rowland, Co-Chair; Aubrey Bonde, Co-Chair; Joshua Bonde; David Elliott; Lee Hall; Jerry Harris; Andrew Milner; Eric Roberts EXECUTIVE COMMITTEE Philip Currie, President; Blaire Van Valkenburgh, Past President; Catherine Forster, Vice President; Christopher Bell, Secretary; Ted Vlamis, Treasurer; Julia Clarke, Member at Large; Kristina Curry Rogers, Member at Large; Lars Werdelin, Member at Large SYMPOSIUM CONVENORS Roger B.J. Benson, Richard J. Butler, Nadia B. Fröbisch, Hans C.E. Larsson, Mark A. Loewen, Philip D. Mannion, Jim I. Mead, Eric M. Roberts, Scott D. Sampson, Eric D. Scott, Kathleen Springer PROGRAM COMMITTEE Jonathan Bloch, Co-Chair; Anjali Goswami, Co-Chair; Jason Anderson; Paul Barrett; Brian Beatty; Kerin Claeson; Kristina Curry Rogers; Ted Daeschler; David Evans; David Fox; Nadia B. Fröbisch; Christian Kammerer; Johannes Müller; Emily Rayfield; William Sanders; Bruce Shockey; Mary Silcox; Michelle Stocker; Rebecca Terry November 2011—PROGRAM AND ABSTRACTS 1 Members and Friends of the Society of Vertebrate Paleontology, The Host Committee cordially welcomes you to the 71st Annual Meeting of the Society of Vertebrate Paleontology in Las Vegas.
    [Show full text]
  • Geological Survey of Ohio
    GEOLOGICAL SURVEY OF OHIO. VOL. I.—PART II. PALÆONTOLOGY. SECTION II. DESCRIPTIONS OF FOSSIL FISHES. BY J. S. NEWBERRY. Digital version copyrighted ©2012 by Don Chesnut. THE CLASSIFICATION AND GEOLOGICAL DISTRIBUTION OF OUR FOSSIL FISHES. So little is generally known in regard to American fossil fishes, that I have thought the notes which I now give upon some of them would be more interesting and intelligible if those into whose hands they will fall could have a more comprehensive view of this branch of palæontology than they afford. I shall therefore preface the descriptions which follow with a few words on the geological distribution of our Palæozoic fishes, and on the relations which they sustain to fossil forms found in other countries, and to living fishes. This seems the more necessary, as no summary of what is known of our fossil fishes has ever been given, and the literature of the subject is so scattered through scientific journals and the proceedings of learned societies, as to be practically inaccessible to most of those who will be readers of this report. I. THE ZOOLOGICAL RELATIONS OF OUR FOSSIL FISHES. To the common observer, the class of Fishes seems to be well defined and quite distin ct from all the other groups o f vertebrate animals; but the comparative anatomist finds in certain unusual and aberrant forms peculiarities of structure which link the Fishes to the Invertebrates below and Amphibians above, in such a way as to render it difficult, if not impossible, to draw the lines sharply between these great groups.
    [Show full text]
  • Early Tetrapod Relationships Revisited
    Biol. Rev. (2003), 78, pp. 251–345. f Cambridge Philosophical Society 251 DOI: 10.1017/S1464793102006103 Printed in the United Kingdom Early tetrapod relationships revisited MARCELLO RUTA1*, MICHAEL I. COATES1 and DONALD L. J. QUICKE2 1 The Department of Organismal Biology and Anatomy, The University of Chicago, 1027 East 57th Street, Chicago, IL 60637-1508, USA ([email protected]; [email protected]) 2 Department of Biology, Imperial College at Silwood Park, Ascot, Berkshire SL57PY, UK and Department of Entomology, The Natural History Museum, Cromwell Road, London SW75BD, UK ([email protected]) (Received 29 November 2001; revised 28 August 2002; accepted 2 September 2002) ABSTRACT In an attempt to investigate differences between the most widely discussed hypotheses of early tetrapod relation- ships, we assembled a new data matrix including 90 taxa coded for 319 cranial and postcranial characters. We have incorporated, where possible, original observations of numerous taxa spread throughout the major tetrapod clades. A stem-based (total-group) definition of Tetrapoda is preferred over apomorphy- and node-based (crown-group) definitions. This definition is operational, since it is based on a formal character analysis. A PAUP* search using a recently implemented version of the parsimony ratchet method yields 64 shortest trees. Differ- ences between these trees concern: (1) the internal relationships of aı¨stopods, the three selected species of which form a trichotomy; (2) the internal relationships of embolomeres, with Archeria
    [Show full text]
  • A Juvenile Skeleton of the Nectridean Amphibian
    Lucas, S.G. and Zeigler, K.E., eds., 2005, The Nonmarine Permian, New Mexico Museum of Natural Histoiy and Science Bulletin No. 30. 39 A JUVENILE SKELETON OF THE NECTRIDEAN AMPHIBIAN DIPLOCAULUS AND ASSOCIATED FLORA AND FAUNA FROM THE MITCHELL CREEK FLATS LOCALITY (UPPER WAGGONER RANCH FORMATION; EARLY PERMIAN), BAYLOR COUNTY, NORTH- CENTRAL TEXAS, USA DAN S. CHANEY, HANS-DIETER SUES AND WILLIAM A. DIMICHELE Department of Paleobiology MRC-121, National Museum of Natural History, PC Box 37012, Washington, D.C. 20013-7021 Abstract—A well-preserved skeleton of a tiny individual of the nectridean amphibian Diplocaulus was found in association with other Early Permian animal remains and a flora in a gray mudstone at a site called Mitchell Creek Flats in Baylor County, north-central Texas. The locality has the sedimentological attributes of a pond deposit. The skeleton of Diplocaulus sp. is noteworthy for its completeness and small size, and appears to represent a juvenile individual. The associated plant material is beautifully preserved and comprises the sphe- nopsids Annularia and Calamites, the conifer IBrachyphyllum, possible cycads represented by one or possibly two forms of Taeniopteris, three gigantopterids - Delnortea, Cathaysiopteris, and Gigantopteridium — and three unidentified callipterids. Several unidentified narrow trunks were found at the base of the deposit, appar- ently washed up against the northern margin of the pond. Other faunal material from the deposit comprises myalinid bivalves, conchostracans, a tooth of a xenacanthid shark, and a palaeonisciform fish. INTRODUCTION Wchita Rver T ^ Coinage i ^ 1 t Complete skeletons of Early Permian vertebrates are rare in north- FwmatJon Grcyp c central Texas, where much collecting has been done for about 150 years c c (Fig.
    [Show full text]
  • Morphology and Evolutionary Significance of the Atlas−Axis Complex in Varanopid Synapsids
    Morphology and evolutionary significance of the atlas−axis complex in varanopid synapsids NICOLÁS E. CAMPIONE and ROBERT R. REISZ Campione, N.E. and Reisz, R.R. 2011. Morphology and evolutionary significance of the atlas−axis complex in varanopid synapsids. Acta Palaeontologica Polonica 56 (4): 739–748. The atlas−axis complex has been described in few Palaeozoic taxa, with little effort being placed on examining variation of this structure within a small clade. Most varanopids, members of a clade of gracile synapsid predators, have well pre− served atlas−axes permitting detailed descriptions and examination of morphological variation. This study indicates that the size of the transverse processes on the axis and the shape of the axial neural spine vary among members of this clade. In particular, the small mycterosaurine varanopids possess small transverse processes that point posteroventrally, and the axial spine is dorsoventrally short, with a flattened dorsal margin in lateral view. The larger varanodontine varanopids have large transverse processes with a broad base, and a much taller axial spine with a rounded dorsal margin in lateral view. Based on outgroup comparisons, the morphology exhibited by the transverse processes is interpreted as derived in varanodontines, whereas the morphology of the axial spine is derived in mycterosaurines. The axial spine anatomy of Middle Permian South African varanopids is reviewed and our interpretation is consistent with the hypothesis that at least two varanopid taxa are present in South Africa, a region overwhelmingly dominated by therapsid synapsids and parareptiles. Key words: Synapsida, Varanopidae, Mycterosaurinae, Varanodontinae, atlas−axis complex, axial skeleton, Middle Permian, South Africa.
    [Show full text]
  • Gondwana Vertebrate Faunas of India: Their Diversity and Intercontinental Relationships
    438 Article 438 by Saswati Bandyopadhyay1* and Sanghamitra Ray2 Gondwana Vertebrate Faunas of India: Their Diversity and Intercontinental Relationships 1Geological Studies Unit, Indian Statistical Institute, 203 B. T. Road, Kolkata 700108, India; email: [email protected] 2Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur 721302, India; email: [email protected] *Corresponding author (Received : 23/12/2018; Revised accepted : 11/09/2019) https://doi.org/10.18814/epiiugs/2020/020028 The twelve Gondwanan stratigraphic horizons of many extant lineages, producing highly diverse terrestrial vertebrates India have yielded varied vertebrate fossils. The oldest in the vacant niches created throughout the world due to the end- Permian extinction event. Diapsids diversified rapidly by the Middle fossil record is the Endothiodon-dominated multitaxic Triassic in to many communities of continental tetrapods, whereas Kundaram fauna, which correlates the Kundaram the non-mammalian synapsids became a minor components for the Formation with several other coeval Late Permian remainder of the Mesozoic Era. The Gondwana basins of peninsular horizons of South Africa, Zambia, Tanzania, India (Fig. 1A) aptly exemplify the diverse vertebrate faunas found Mozambique, Malawi, Madagascar and Brazil. The from the Late Palaeozoic and Mesozoic. During the last few decades much emphasis was given on explorations and excavations of Permian-Triassic transition in India is marked by vertebrate fossils in these basins which have yielded many new fossil distinct taxonomic shift and faunal characteristics and vertebrates, significant both in numbers and diversity of genera, and represented by small-sized holdover fauna of the providing information on their taphonomy, taxonomy, phylogeny, Early Triassic Panchet and Kamthi fauna.
    [Show full text]
  • C.-Shoulder Joint
    59.14.98,1:81 Article X.-THE LOCOMOTOR APPARATUS OF CERTAIN PRIMITIVE AND MAMMAL-LIKE REPTILES' BY ALFRED S. ROMER PLATES XXVII TO XLVI TABLE OF CONTENTS PAGE INTRODIUCTION ......................................................... 519 FORE LIMB, MIUSCULATURE ............................................. 524 1.-Trapezius (and sterno-cleido-mastoideus) ........................ 524 2.-Axial muscles acting on the girdle ............................... 525 a.-Dorsal: levator scapul& (and atlanto-scapularis, atlanto- acromialis or omo-trachelius and rhomboideuA), serratus anterior .............................................. 525 b.-Ventral: sterno- (episterno) hyoideus and omo-hyoideus, sterno-costo-coracoidei (subclavius) ................... 526 3.-Latissimus dorsi and teres major ................................ 527 4.-Pectoralis ..................................................... 528 5.-Deltoid ....................................................... 529 6.-Subcoraco-scapularis and scap'ilo-humeralis posterior (subscapularis) 530 7.-Scapulo-humeralis anterior (teres minor), supracoracoideus (supra- and infraspinatus), and coraco-brachialis ..................... 532 8.-Biceps and brachialis .......................................... 536 9.-Triceps ............................... A 537 10.-Brachio- (humero-) radialis (supinator longus) and supinator ...... 538 11.-Forearm: extensors............................................. 539 12.-Forearm: flexors (includingpronators) ............................ 540 13.-Groupingof forelimb muscles
    [Show full text]