DOCSLIB.ORG

The Enamel Ultrastructure of Multituberculate Mammals: a Review

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Enamel Ultrastructure of Multituberculate Mammals: a Review Scanning Electron Microscopy Volume 1986 Number 4 Article 35 10-9-1986 The Enamel Ultrastructure of Multituberculate Mammals: A Review D. W. Krause State University of New York S. J. Carlson University of California, Davis Follow this and additional works at: https://digitalcommons.usu.edu/electron Part of the Life Sciences Commons Recommended Citation Krause, D. W. and Carlson, S. J. (1986) "The Enamel Ultrastructure of Multituberculate Mammals: A Review," Scanning Electron Microscopy: Vol. 1986 : No. 4 , Article 35. Available at: https://digitalcommons.usu.edu/electron/vol1986/iss4/35 This Article is brought to you for free and open access by the Western Dairy Center at DigitalCommons@USU. It has been accepted for inclusion in Scanning Electron Microscopy by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. SCANNING ELECTRON MICROSCOPY /1986/IV (Pages 1591-1607) 0586-5581/86$1.00+05 SEM Inc., AMF O'Hare (Chicago), IL 60666-0507 USA THE ENAMELULTRASTRUCTURE OF MULTITUBERCULATEMAMMALS: A REVIEW 1* 2 D. W, Krause and S. J, Carlson 1Department of Anatomical Sciences, State UnivP.rsity of New York, Stony Brook, New York 11794 2Museum of Paleontology and Department of Geological Sciences, The University of Michigan, Ann Arbor, Michigan 48109 2Present address: Department of Geology, University of California Davis, CA 95616 (Received for publication May 09, 1986, and in revised form October 09, 1986) Abstract Introduction The enamel ultrastructure of multituber­ The enamel ultrastructure of multituber­ culate mammals has been sampled extensively and culate mammals has been sampled extensively and studied intensively and is better known than for studied intensively; it is better known than for any other group of early mammals. The enamel of any other group of early mammals, and perhaps for the earliest multituberculates, those of the Late any other group of fossil mammals save hominoids. Triassic-Early Jurassic suborder Haramiyoidea and Only recently, with the advent of technological the Late Jurassic-early Early Cretaceous suborder advances in scanning electron microscopy, have Plagiaulacoidea, is "preprismatic." With only concerted efforts been made to investigate two exceptions, all Late Cretaceous and early systematically the enamel ultrastructure of Tertiary genera of multituberculates examined mammals for the purpose of providing a new and have prismatic enamel. Prisms are either small independent data set with which to test phylo­ with circular (complete) boundaries or large with genetic hypotheses based on gross morphological arc-shaped (incomplete) boundaries. There is a characters alone (e.g., Gantt et al. 1977; Boyde remarkably consistent relationship between enamel 1978; Vrba and Grine 1978; Gantt 1980, 1983; von ultrastructural type and subordinal taxa in that Koenigswald 1982; Boyde and Martin 1984a, b; small, circular prisms are usually found within Grine et al., 1986a). Historically, multituber­ the suborder Ptilodontoidea and large, arc-shaped culate phylogeny has been determined almost prisms are usually found in the suborder Taenio­ exclusively on the basis of a few gross dental labidoidea and in six Late Cretaceous-Early characters that have proven inadequate to dis­ Tertiary genera of indeterminate subordinal criminate consistently between higher taxa. status. Cranial and postcranial characters are imprac­ Research currently in progress suggests that tical to employ in phylogenetic analyses of both small, circular prisms and large, arc-shaped multituberculates because adequate material is prisms are homologous in all multituberculates in rare. Thus, multituberculates have served as the which they occur, with one exception. Neolio­ focus of considerable research on enamel ultra­ tomus, a taeniolabidoid, appears to have evolved structure because, even though they were among small, circular prisms independently. In addi­ the most evolutionarily successful and taxonom­ tion, it appears that large, arc-shaped prisms ically long-lived of early mammals, their taxon­ represent the primitive condition in multituber­ omy and systematics have been, and still are, in culates with prismatic enamel, not small, circ­ disarray. ular prisms as has been proposed previously. The objectives of this paper are to review and discuss what has been learned from past studies about the enamel ultrastructure of the Multituberculata, to re-evaluate some of that work in the light of previously unpublished data, and to present some preliminary conclusions concerning the homology and polarity of multi­ tuberculate enamel ultrastructural characters. In addition, we wish to suggest some areas for KEY WORDS: Enamel ultrastructure, multituber­ future research on these subjects. But first it culates, mammals, phylogeny, cladistics, homo­ is necessary to provide, as background infor­ logy, polarity, Mesozoic, Paleogene, variability mation, a brief account of the evolutionary history and paleobiological attributes of multi­ tuberculates. *Address for correspondence: David W. Krause, Department of Anatomical What Are Multituberculates? Sciences, State University of New York, Stony Brook, New York 11794 The Multituberculata is the longest-lived Phone No. (516) 444-3117 order of mammals. Their known geologic record is 1591 D, W. Krause and S. J. Carlson from the Late Triassic to the early Oligocene, an Table 1. Classification of multituberculates interval of over 150 million years. Multituber­ (Hahn and Hahn 1983). culates, unlike their dinosaurian contemporaries, survived the Cretaceous-Tertiary boundary with Order MULTITUBERCULATA little apparent ill effect (Archibald 1983). Suborder HARAMIYOIDEA Representatives of the order have been found only Family HARAMIYIDAE on northern continents: in the Late Jurassic to Haramiya, Thomasia, ?Hypsiprymnopsis early Oligocene of North America, in the Late Suborder PLAGIAULACOIDEA Triassic to early Eocene of Europe, and in the Family ARGINBAATARIDAE Early Cretaceous to early Eocene of Asia (Clemens Arginbaatar and Kielan-Jaworowska 1979; Hahn and Hahn 1983). Family Paulchoffatiidae The Order Multituberculata is both a taxonomical­ Subfamily Kuehneodontinae ly diverse and numerically abundant group that Bolodon, Guimarotodon, Henkelodon, includes 57 named genera and over 140 named Kuehneodon, Plioprion species (Hahn and Hahn 1983). During the Late Subfamily Paulchoffatiinae Cretaceous, they comprised as much as 75% of the Paulchoffatia, Pseudobolodon individuals in mammalian local faunas (Van Valen Subfamily indeterminate and Sloan 1966). They appear to have attained Parendotherium peak species diversity in the middle Paleocene, Family Plagiaulacidae approximately 60 million years before present Ctenacodon, Loxaulax, Plagiaulax, (Van Valen and Sloan 1966; Krause 1980). Psalodon The relationships of multituberculates to Suborder PTILODONTOIDEA other higher taxa of mammals are obscure. They Family BOFFIIDAE have long been grouped with docodonts, tricono­ Boffius donts, and monotremes as nontherian mammals, a Family CIMOLODONTIDAE taxonomic arrangement that has recently been Anconodon, Cimolodon, Liotomus challenged (e.g., Presley 1981; Kemp 1982, 1983; Family NEOPLAGIAULACIDAE Archer et al. 1985). Ectypodus, Mesodma, Mimetodon, The Order Multituberculata is generally Neoplagiaulax, Parectypodus, divided into three suborders: Plagiaulacoidea, Xanclomys Ptilodontoidea, and Taeniolabidoidea. Most Family PTILODONTIDAE workers (e.g., Hahn 1973; McKenna 1975; Sloan Kimbetohia, Prochetodon, Ptilodus 1979) also include an enigmatic and poorly known Suborder TAENIOLABIDOIDEA Late Triassic and Early Jurassic (possibly middle Family EUCOSMODONTIDAE Jurassic) group from Europe, the suborder Hara­ Subfamily BUGINBAATARINAE miyoidea, in the Multituberculata (a possible Buginbaatar haramiyid has been described recently from the Subfamily EUCOSMODONTINAE Late Triassic/Early Jurassic of North America Bulganbaatar, Chulsanbaatar, (Jenkins et al. 1983)). The Plagiaulacoidea are Eucosmodon, Kryptobaatar, a Late Jurassic to Early Cretaceous group con­ Nemegtbaatar, Neoliotomus, Stygimys, taining 13 genera, the Ptilodontoidea a Late Tugrigbaatar, ?Xyronomys Cretaceous to early Oligocene group also con­ Subfamily MICROCOSMODONTINAE taining 13 genera, and the Taeniolabidoidea a Acheronodon, Microcosmodon, Late Cretaceous to early Eocene group containing Pentacosmodon 20 genera. Eight Late Cretaceous and early Subfamily SLOANBATAARIDAE Tertiary genera (Allacodon, Cimexomys, Cimolomys, Sloanbaatar Essonodon, Hainina, Meniscoessus, Paracimexomys, Family TAENIOLABIDIDAE and Viridomys), most of which, until recently, Catopsalis, Kamptobaatar, were included in either the Ptilodontoidea or Lambdopsalis, Prionessus, Taeniolabidoidea, are currently placed in Sub­ Sphenopsalis, Taeniolabis order incertae sedis. Table 1, based upon a Suborder indeterminate compilation by Hahn and Hahn (1983), presents the Family CIMOLOMYIDAE most recent comprehensive classification of all Cimolomys, Meniscoessus, ?Essonodon genera currently allocated to the Multitubercu­ Family indeterminate lata. Allacodon, Cimexomys, Hainina, Multituberculates are so-named because of Paracimexomys, Viridomys the possession of multiple cusps, arranged in longitudinal rows, on the molars. Plagiaulacoids are characterized by a greater number of incisors fragmentary cranial material of ptilodontoids and premolars than later forms, ptilodontoids by from North America suggests that these forms were an enlarged, blade-like
Load more

Recommended publications
  • Dome-Headed, Small-Brained Island Mammal from the Late Cretaceous of Romania
    Dome-headed, small-brained island mammal from the Late Cretaceous of Romania Zoltán Csiki-Savaa,1, Mátyás Vremirb, Jin Mengc, Stephen L. Brusatted, and Mark A. Norellc aLaboratory of Paleontology, Faculty of Geology and Geophysics, University of Bucharest, 010041 Bucharest, Romania; bDepartment of Natural Sciences, Transylvanian Museum Society, 400009 Cluj-Napoca, Romania; cDivision of Paleontology, American Museum of Natural History, New York, NY 10024; and dSchool of GeoSciences, Grant Institute, University of Edinburgh, EH9 3FE Edinburgh, United Kingdom Edited by Neil H. Shubin, The University of Chicago, Chicago, IL, and approved March 26, 2018 (received for review January 20, 2018) The island effect is a well-known evolutionary phenomenon, in describe the anatomy of kogaionids in detail, include them in a which island-dwelling species isolated in a resource-limited envi- comprehensive phylogenetic analysis, estimate their body sizes, ronment often modify their size, anatomy, and behaviors compared and present a reconstruction of their brain and sense organs. with mainland relatives. This has been well documented in modern This species exhibits several features that we interpret as re- and Cenozoic mammals, but it remains unclear whether older, more lated to its insular habitat, most notably a brain that is sub- primitive Mesozoic mammals responded in similar ways to island stantially reduced in size compared with close relatives and habitats. We describe a reasonably complete and well-preserved skeleton of a kogaionid, an enigmatic radiation of Cretaceous island- mainland contemporaries, demonstrating that some Mesozoic dwelling multituberculate mammals previously represented by frag- mammals were susceptible to the island effect like in more mentary fossils.
    [Show full text]
  • Functional Tests of the Competitive Exclusion Hypothesis For
    Functional tests of the competitive exclusion royalsocietypublishing.org/journal/rsos hypothesis for multituberculate extinction Research Cite this article: Adams NF, Rayfield EJ, Cox PG, Neil F. Adams1,†, Emily J. Rayfield1, Philip G. Cox2,3, Cobb SN, Corfe IJ. 2019 Functional tests of the 2,3 4 competitive exclusion hypothesis for Samuel N. Cobb and Ian J. Corfe multituberculate extinction. R. Soc. open sci. 6: 1School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK 181536. 2Department of Archaeology, University of York, York YO1 7EP, UK http://dx.doi.org/10.1098/rsos.181536 3Centre for Anatomical and Human Sciences, Hull York Medical School, University of York, York YO10 5DD, UK 4Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland NFA, 0000-0003-2539-5531; EJR, 0000-0002-2618-750X; Received: 11 September 2018 PGC, 0000-0001-9782-2358; SNC, 0000-0002-8360-8024; Accepted: 21 February 2019 IJC, 0000-0002-1824-755X Multituberculate mammals thrived during the Mesozoic, but their diversity declined from the mid-late Paleocene Subject Category: onwards, becoming extinct in the late Eocene. The radiation of Biology (whole organism) superficially similar, eutherian rodents has been linked to multituberculate extinction through competitive exclusion. Subject Areas: However, characteristics providing rodents with a supposed palaeontology/evolution/biomechanics competitive advantage are currently unknown and comparative functional tests between the two groups are lacking. Here, a Keywords: multifaceted approach
    [Show full text]
  • Enamel Ultrastructure of Multituberculate Mammals: an Investigation of Variability
    CO?JTRIBI!TIONS FROM THE MUSEUM OF PALEOK.1-OLOCiY THE UNIVERSITY OF MICHIGAN VOL. 27. NO. 1, p. 1-50 April I, 1985 ENAMEL ULTRASTRUCTURE OF MULTITUBERCULATE MAMMALS: AN INVESTIGATION OF VARIABILITY BY SANDRA J. CARLSON and DAVID W. KRAUSE MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN ANN ARBOR CONTRlBUTlONS FROM THE MUSEUM OF PALEON I OLOGY Philip D. Gingerich, Director Gerald R. Smith. Editor This series of contributions from the Museum of Paleontology is a medium for the publication of papers based chiefly upon the collection in the Museum. When the number of pages issued is sufficient to make a volume, a title page and a table of contents will be sent to libraries on the mailing list, and to individuals upon request. A list of the separate papers may also be obtained. Correspondence should be directed to the Museum of Paleontology, The University of Michigan, Ann Arbor, Michigan, 48109. VOLS. 11-XXVI. Parts of volumes may be obtained if available. Price lists available upon inquiry. CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN Vol . 27, no. 1, p. 1-50, pub1 ished April 1, 1985, Sandra J. Carlson and David W. Krause (Authors) ERRATA Page 11, Figure 4 caption, first line, should read "(1050X)," not "(750X)." ENAMEL ULTRASTRUCTURE OF MULTITUBERCULATE MAMMALS: AN INVESTIGATION OF VARIABILITY BY Sandra J. Carlsonl and David W. Krause' Abstract.-The nature and extent of enamel ultrastructural variation in mammals has not been thoroughly investigated. In this study we attempt to identify and evaluate the sources of variability in enamel ultrastructural patterns at a number of hierarchic levels within the extinct order Multituberculata.
    [Show full text]
  • AMERICAN MUSEUM NOVITATES Published by Number 267 Tnz AMERICAN Musumof Natural History April 30, 1927
    AMERICAN MUSEUM NOVITATES Published by Number 267 Tnz AMERICAN MUsuMOF NATuRAL HIsTORY April 30, 1927 56.9(117:78.6) MAMMALIAN FAUNA OF THE HELL CREEK FORMATION OF MONTANA BY GEORGE GAYLORD SIMPSON In 1907, Barnum Brown' announced the discovery, in the Hell Creek beds of Montana, of a small number of mammalian teeth. He then listed only Ptilodus sp., Meniscoessus conquistus Cope and Menisco8ssus sp., without description. In connection with recent work on the mammals of the Paskapoo formation of Alberta, this collection was referred to the writer for further study through the kindness of Mr. Brown and of Dr. W. D. Matthew, and a brief consideration of it is here presented. The material now available consists of two lots, one collected in 1906 by Brown and Kaisen, the other part of the Cameron Collection. The latter has no definite data as to locality save "the vicinity of Forsyth, Montana, and Snow Creek," and is thus from a region intermediate between the locality of the other Hell Creek specimens and that of the Niobrara County, Wyoming, Lance, but much nearer the former. Brown's collection is from near the head of Crooked Creek, in Dawson County, about eleven miles south of the Missouri River, Crooked Creek joining the latter about four miles northeast of the mouth of Hell Creek, along which are the type exposures of the formation. The mammals agree with the other palaeontological data in being of Lance age, although slightly different in detail from the Wyoming Lance fauna. The only localities now known for mammals of Lance age are the present ones, the classical Niobrara County Lance outcrops whence came all of Marsh's specimens, and an unknown point or points in South Dakota where Wortman found the types of Meniscoessus conquistus Cope and Thlzeodon padanicus Cope.
    [Show full text]
  • Multituberculate Mammals from the Wahweap
    MULTITUBERCULATE MAMMALS FROM THE WAHWEAP (CAMPANIAN, AQUILAN) AND KAIPAROWITS (CAMPANIAN, JUDITHIAN) FORMATIONS, WITHIN AND NEAR GRAND STAIRCASE-ESCALANTE NATIONAL MONUMENT, SOUTHERN UTAH Jeffrey G. Eaton Department of Geosciences Weber State University Ogden, UT 84408-2507 phone: (801) 626-6225 fax: (801) 626-7445 e-mail: [email protected] Cover photo by author: Powell Point in “The Blues,” the early Tertiary Claron Formation on the horizon and the Kaiparowits Formation in the foreground. ISBN 1-55791-665-9 Reference to any specific commercial product by trade name, trademark, or manufacturer does not constitute endorsement or recommendation by the Utah Geological Survey MISCELLANEOUS PUBLICATION 02-4 UTAH GEOLOGICAL SURVEY a division of 2002 Utah Department of Natural Resources STATE OF UTAH Michael O. Leavitt, Governor DEPARTMENT OF NATURAL RESOURCES Robert Morgan, Executive Director UTAH GEOLOGICAL SURVEY Richard G. Allis, Director UGS Board Member Representing Robert Robison (Chairman) ...................................................................................................... Minerals (Industrial) Geoffrey Bedell.............................................................................................................................. Minerals (Metals) Stephen Church .................................................................................................................... Minerals (Oil and Gas) E.H. Deedee O’Brien .......................................................................................................................
    [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]
  • Lhiwanj[Fuseum
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by American Museum of Natural History Scientific... >lhiwanJ[fuseum PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK 24, N.Y. NUMBER 2 2 26 AUGUST I7, I 965 First Evidence of Tooth Replacement in the Subclass Allotheria (Mammalia) BY FREDERICK S. SZALAY1 INTRODUCTION Multituberculates (the only known order of the subclass Allotheria) are abundantly represented in Mesozoic and Paleocene mammal locali- ties. Of the relatively large number of multituberculate mandibles and maxillae known up to the summer of 1963, not one showed a tooth in the process of replacement. Young specimens were known with less fully erupted teeth (Jepsen, 1940, p. 245; Clemens, 1963, p. 34), but it has not been possible before to demonstrate diphyodonty in multituberculates. With a now-standardized washing technique used for obtaining ver- tebrate microfossils (Hibbard, 1949; McKenna, 1962), a vertebrate paleontology field party of the American Museum of Natural History collected a large assemblage of vertebrate fossils during the summer of 1963. The collection was of approximately Torrejonian age from the eastern part of the Washakie Basin in southern Wyoming.2 Among the large number of multituberculates represented, a fragmentary left man- dible (A.M.N.H. No. 83003) is one of the two specimens described in the present paper that supply the first direct evidence of allotherian tooth replacement. The deciduous lower incisor is still present in the mandible, 1 Department of Zoology, Columbia University, New York, New York.
    [Show full text]
  • Craniodental Anatomy of a New Late Cretaceous Multituberculate Mammal from Udan Sayr, Mongolia
    University of Louisville ThinkIR: The University of Louisville's Institutional Repository Electronic Theses and Dissertations 8-2014 Craniodental anatomy of a new late cretaceous multituberculate mammal from Udan Sayr, Mongolia. Amir Subhash Sheth University of Louisville Follow this and additional works at: https://ir.library.louisville.edu/etd Part of the Anatomy Commons, and the Medical Neurobiology Commons Recommended Citation Sheth, Amir Subhash, "Craniodental anatomy of a new late cretaceous multituberculate mammal from Udan Sayr, Mongolia." (2014). Electronic Theses and Dissertations. Paper 1317. https://doi.org/10.18297/etd/1317 This Master's Thesis is brought to you for free and open access by ThinkIR: The nivU ersity of Louisville's Institutional Repository. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of ThinkIR: The nivU ersity of Louisville's Institutional Repository. This title appears here courtesy of the author, who has retained all other copyrights. For more information, please contact [email protected]. CRANIODENTAL ANATOMY OF A NEW LATE CRETACEOUS MULTITUBERCULATE MAMMAL FROM UDAN SAYR, MONGOLIA By Amir Subhash Sheth B.A., Centre College, 2010 A Thesis Submitted to the Faculty of the School of Medicine of the University of Louisville in Partial Fulfillment of the Requirements for the Degree of Master of Science Department of Anatomical Sciences and Neurobiology University of Louisville Louisville, Kentucky August 2014 CRANIODENTAL ANATOMY OF A NEW LATE CRETACEOUS MULTITUBERCULATE MAMMAL FROM UDAN SAYR, MONGOLIA By Amir Subhash Sheth B.A., Centre College, 2010 A Thesis Approved on July 18th, 2014 By the Following Thesis Committee: ________________________________ (Guillermo W.
    [Show full text]
  • Mammals from the Mesozoic of Mongolia
    Mammals from the Mesozoic of Mongolia Introduction and Simpson (1926) dcscrihed these as placental (eutherian) insectivores. 'l'he deltathcroids originally Mongolia produces one of the world's most extraordi- included with the insectivores, more recently have narily preserved assemblages of hlesozoic ma~nmals. t)een assigned to the Metatheria (Kielan-Jaworowska Unlike fossils at most Mesozoic sites, Inany of these and Nesov, 1990). For ahout 40 years these were the remains are skulls, and in some cases these are asso- only Mesozoic ~nanimalsknown from Mongolia. ciated with postcranial skeletons. Ry contrast, 'I'he next discoveries in Mongolia were made by the Mesozoic mammals at well-known sites in North Polish-Mongolian Palaeontological Expeditions America and other continents have produced less (1963-1971) initially led by Naydin Dovchin, then by complete material, usually incomplete jaws with den- Rinchen Barsbold on the Mongolian side, and Zofia titions, or isolated teeth. In addition to the rich Kielan-Jaworowska on the Polish side, Kazi~nierz samples of skulls and skeletons representing Late Koualski led the expedition in 1964. Late Cretaceous Cretaceous mam~nals,certain localities in Mongolia ma~nmalswere collected in three Gohi Desert regions: are also known for less well preserved, but important, Bayan Zag (Djadokhta Formation), Nenlegt and remains of Early Cretaceous mammals. The mammals Khulsan in the Nemegt Valley (Baruungoyot from hoth Early and Late Cretaceous intervals have Formation), and llcrmiin 'ISav, south-\vest of the increased our understanding of diversification and Neniegt Valley, in the Red beds of Hermiin 'rsav, morphologic variation in archaic mammals. which have heen regarded as a stratigraphic ecluivalent Potentially this new information has hearing on the of the Baruungoyot Formation (Gradzinslti r't crl., phylogenetic relationships among major branches of 1977).
    [Show full text]
  • Vertebrate Paleontology of the Cretaceous/Tertiary Transition of Big Bend National Park, Texas (Lancian, Puercan, Mammalia, Dinosauria, Paleomagnetism)
    Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1986 Vertebrate Paleontology of the Cretaceous/Tertiary Transition of Big Bend National Park, Texas (Lancian, Puercan, Mammalia, Dinosauria, Paleomagnetism). Barbara R. Standhardt Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Standhardt, Barbara R., "Vertebrate Paleontology of the Cretaceous/Tertiary Transition of Big Bend National Park, Texas (Lancian, Puercan, Mammalia, Dinosauria, Paleomagnetism)." (1986). LSU Historical Dissertations and Theses. 4209. https://digitalcommons.lsu.edu/gradschool_disstheses/4209 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This reproduction was made from a copy of a manuscript sent to us for publication and microfilming. While the most advanced technology has been used to pho­ tograph and reproduce this manuscript, the quality of the reproduction is heavily dependent upon the quality of the material submitted. Pages in any manuscript may have indistinct print. In all cases the best available copy has been filmed. The following explanation of techniques is provided to help clarify notations which may appear on this reproduction. 1. Manuscripts may not always be complete. When it is not possible to obtain missing pages, a note appears to indicate this. 2. When copyrighted materials are removed from the manuscript, a note ap­ pears to indicate this. 3.
    [Show full text]
  • The Braincase of Two Late Cretaceous Asian Multituberculates Studied by Serial Sections
    The braincase of two Late Cretaceous Asian multituberculates studied by serial sections J0RN H. HURUM Hurum, J.H. 1998. The braincase of two Late Cretaceous Asian multituberculatesstudied by serial sections. -Acta Palaeontologica Polonica 43, 1, 21-52. The braincase structure of two Late Cretaceous Mongolian djadochtatherian multituber- culates Nemegtbaatar gobiensis and Chulsanbaatar vulgaris from the ?late Campanian of Mongolia is presented based on the two serially sectioned skulls and additional specimens. Reconstructions of the floor of the braincase in both taxa are given. The complete intracranial sphenoid region is reconstructed for the first time in multitubercu- lates. Cavum epiptericum is a separate space with the taenia clino-orbitalis (ossified pila antotica) as the medial wall, anterior lamina of the petrosal and possibly the alisphenoid as the lateral wall, and the basisphenoid, petrosal and possibly alisphenoid ventrally. The fovea hypochiasmatica is shallow, tuberculurn sellae is wide and more raised from the skull base than it is in the genus Pseudobolodon. The dorsal opening of the carotid canal is situated in the fossa hypophyseos. The taenia clino-orbitalis differs from the one described in Pseudobolodon and Lambdopsalis in possessing just one foramen (metoptic foramen). Compared to all extant mammals the braincase in Nemegtbaatar and Chulsan- baatar is primitive in that both the pila antotica and pila metoptica are retained. In both genera the anterior lamina of the petrosal is large with a long anterodorsal process while the alisphenoid is small. A review is given of the cranial anatomy in Nemegtbaatar and Chulsanbaatar. K e y w o r d s : Braincase structure, sphenoid complex, cavum epiptericum,Mammalia, Multituberculata,Djadochtatheria, Cretaceous, Mongolia.
    [Show full text]
  • Continental Tertiary Basins and Associated Deposits of Aragón and Catalunya
    CHAPTER16 CONTINENTAL TERTIARY BASINS AND ASSOCIATED DEPOSITS OF ARAGÓN AND CATALUNYA Aragonian type series (stratotype) behind the village of Villafeliche, near the Jiloca river. Élez, J. One of the main problems in stratigraphy and paleon- surrounded by orogens (overthrusted units of the tology is the correlation between the sediments and Pyrenees to the north, the Iberian Mountain Range to faunas of continental and marine origin, originated the south, and the Catalan-Coastal Mountain Range by the difficulty to establish a parallelism between to the east). It responds to a general compression gen- the respective biostratigraphic scales. That is why the erated as a consequence of the shortening between stratigraphy of the continental Tertiary basins and the the Iberian and European plates. In this basin there associated vertebrate deposits in Aragón and Cataluña is an important paleontological area forming a wide are of great international relevance. fringe parallel to the Catalan orogen and attached to the Catalan-Coastal Mountain Range. There are some The Lower Tertiary (Paleogene) continental series of other more scattered but less important areas in the Aragón and Cataluña, with good exposures and abun- interior, both of Cataluña and Aragón. dant deposits, are exceptional cases in the European framework as their biostratigraphy is correlatable to The other model of continental Tertiary sedimenta- marine sediments. In the Upper Tertiary (Neogene), its tion for these regions corresponds to the so called importance is even bigger, since unique stratigraphic intramontane basins, with smaller tectonic graben or series crop out with numerous deposits which allowed semigraben morphologies and filled faster. As a norm, a better accuracy in the continental time scales.
    [Show full text]