DOCSLIB.ORG

The Internal Cranial Anatomy of Champsosaurus Lindoei and Its Functional Implications by Thomas William Dudgeon a Thesis Submitt

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Internal Cranial Anatomy of Champsosaurus Lindoei and Its Functional Implications by Thomas William Dudgeon a Thesis Submitt The internal cranial anatomy of Champsosaurus lindoei and its functional implications by Thomas William Dudgeon A thesis submitted to the Faculty of Graduate and Postdoctoral Affairs in partial fulfilment of the requirements for the degree of Master of Science in Earth Sciences Carleton University Ottawa, Ontario © 2019 Thomas William Dudgeon Abstract Although Champsosaurus is well-known in Late Cretaceous and Paleocene deposits of North America, their cranial anatomy is poorly understood. Here, a well- preserved skull of Champsosaurus lindoei is described in detail using high-resolution micro-CT scanning. This confirms the presence of the putative neomorphic bone, which may be homologous with the pre-existing stapes, or developed through incomplete fusion of dermatocranial ossification centres. The ventral openings on the skull of Champsosaurus relate to the fenestrae ovales, an unusual configuration that may be convergent with other aquatic reptiles. Overall, the endocranial anatomy of Champsosaurus is typical for a basal diapsid. The morphology of the pars inferior of the inner ear suggests that Champsosaurus were capable of detecting sound underwater, and geometric morphometric analyses of the semicircular canals suggests that they were specialized for detecting head movements in an aquatic environment. Taken together, these results suggest that Champsosaurus were well adapted for an aquatic lifestyle. ii Acknowledgements I would like to thank Dr. Jordan Mallon and Dr. Hillary Maddin for their supervision and guidance throughout this project, Dr. Michael Ryan and Dr. Emily Standen for their invaluable feedback, and Dr. David Evans for helping to develop this project and for his advice and assistance along the way. I would like to thank Dr. Danielle Fraser and Bassel Arnaout for patiently teaching me R. Thanks to the staff and students of Carleton University, especially to the Carleton University Palaeontology students, for their support and encouragement. Thanks also to the staff of the Canadian Museum of Nature, Royal Ontario Museum, and the Royal Tyrrell Museum for providing access to their collections. For helpful discussions, I thank Dr. Jason Anderson, Dr. Michael Coldwell, and Dr. Tetsuto Miyashita. Thanks to G. Sobral and the Museum für Naturkunde, K. Andrzewski, M. Polcyn, K. Chapelle, S. Lautenschlager, and H. Maddin for providing CT data, F. Gaidies for CT scanning the Pantherophis specimen, and the University of Texas CT Facility and the Alta Vista Animal Hospital for CT scanning CMN 8920 and CMN 8919, respectively. Special thanks to Zoe Landry, Andrew Dodge, Emmett Janssens, and Eric Guitard, for their moral support and assistance with colour identification. Finally, I would like to thank Mom, Dad, Becky, Zoe, and Gabby for their constant love and support. iii Table of Contents Title Page…………………………………………………………………………………i Abstract…………………………………………………………………………………..ii Acknowledgements……………………………………………………………………...iii Table of Contents………………………………………………………………………..iv List of Tables……………………………………………………………………………vii List of Illustrations……………………………………………………………………...ix List of Appendices……………………………………………………………………...xii Chapter 1: A review of Choristodera (Diapsida)……………………………………..1 Introduction………………………………………………………………….…...1 Institutional Abbreviations…………………………………………………….…5 Systematic Palaeontology…………………………………………………….….6 Discussion…………………………………………………………………….....46 The problem of Champsosaurus…………………………………….......46 The absence of definitions within Choristodera…………………………52 Palaeobiology of Choristodera…………………………………………..55 Cranial anatomy of Choristoderes and its biological implications……...59 Cranial bones and the neomorphic bone………………………...69 Neurosensory anatomy of Champsosaurus……………………...60 Turbinates and thermoregulation………………………………...61 Conclusions……………………………………………………………………....63 Research objectives……………………………………………………………....65 iv Chapter 2: Computed tomography (CT) analysis of the cranium of Champsosaurus lindoei and implications for the choristoderan neomorphic ossification……………66 Introduction……………………………………………………………………....66 Definitions………………………………………………………………..68 Institutional Abbreviations……………………………………………….69 Anatomical Abbreviations……………………………………………….69 Materials and Methods…………………………………………………………...71 Results…………………………………………………………………………....72 Overall skull morphology………………………………………………..72 Dermatocranium………………………………………………………....72 Splanchnocranium………………………………………………………101 Chondrocranium………………………………………………………..103 Discussion………………………………………………………………………113 Conservation of the braincase among amniotes and its implications for the choristoderan neomorphic ossification…………………………………118 Functionality of the choristoderan neomorphic ossification…………....130 Conclusions……………………………………………………………………..132 Chapter 3: The internal anatomy of the skull of Champsosaurus and implications for neurosensory function…………………………………………………………….134 Introduction…………………………………………………………………….134 Materials and methods………………………………………………………….137 Materials………………………………………………………………..137 Scanning and segmentation…………………………………………….139 v Estimation of auditory perception……………………………………....140 Inferring ecology and the endosseous labyrinth………………………..142 Results…………………………………………………………………………..147 Champsosaurus brain endocast…………………………………………147 Cranial nerves…………………………………………………………..152 Endosseous labyrinth…………………………………………………...156 Vasculature……………………………………………………………..158 Nasal cavity……………………………………………………………..159 Auditory capabilities…………………………………………………....161 Geometric morphometrics of the semicircular canals………………….162 Discussion………………………………………………………………………175 The brain endocast……………………………………………………...175 Olfaction………………………………………………………………..178 Vision…………………………………………………………………...180 Hearing………………………………………………………………….181 Phylogeny and the endosseous labyrinth……………………………….189 Ecology and the endosseous labyrinth………………………………….191 Conclusions……………………………………………………………………..197 Chapter 4: Conclusions and future work……………………………………………200 Choristodere taxonomy and systematics………………...……………………..200 Cranial anatomy and the choristoderan neomorphic bone....…………………..203 Neuroanatomy, behaviour, and ecology….…………………………………….204 Final remarks…………………………………………………………………...207 vi Appendices……………………………………………………………………………..208 References……………………………………………………………………………...212 vii List of Tables Table 1.1: Eight dubious species of Champsosaurus and their synonyms……………....37 Table 2.1: Measurements for the skull of Champsosaurus lindoei (CMN 8920)………..78 Table 2.2: A comparison of braincase bones acrossAmniota…………………………..120 Table 3.1: Bloomberg’s K value and associated p-value for both centroid size and landmark coordinates of the endosseous labyrinths…………………………………….168 Table 3.2: ANCOVA of ecology, centroid size, and the interaction between ecology and centroid size against canal shape……………………………………………………….169 Table 3.3: Phylogenetic generalized least squares of semicircular canal shape against ecology, and semicircular canal centroid size………………………………………….170 Table 3.4: Posterior probabilities (10 000 permutations) of significant differences between the ecological groups based on Mahalanobis distances………………………174 Table 3.5: Posterior probabilities (10 000 permutations) and log-likelihood estimates of Champsosaurus species belonging to separate ecological groups……………………..176 viii List of Illustrations Figure 1.1: A phylogeny of Sauria with Choristodera highlighted in red………………...2 Figure 1.2: Time-calibrated phylogeny of Choristodera (from Matsumoto et al., 2019)…3 Figure 1.3: . Reconstructed line drawing of the dorsal and ventral view of the skull of Cteniogenys (modified from Evans 1990)……………………………………………….11 Figure 1.4: Line drawing of Lazarussuchus sp. (modified from Matsumoto et al., 2013)……………………………………………………………………………………..16 Figure 1.5: A nearly complete juvenile Monjurosuchus splendens (modified from Gao et al., 2000)…………………………………………………………………………………19 Figure 1.6: A mature Hyphalosaurus baitaigouensis (from Ji et al., 2010)……………..22 Figure 1.7: The skull of Simoedosaurus dakotensis (modified from Erickson 1987)…...29 Figure 1.8: The skull of Tchoiria (from Ksepka et al., 2005)……………………………31 Figure 1.9: The skull of Ikechosaurus sunailinae (modified from Brinkman and Dong 1993)……………………………………………………………………………………..33 Figure 1.10: The dorsal surface of the skull of Champsosaurus lindoei (CMN 8920)….36 Figure 1.11: Map of North America with reported occurrences of Champsosaurus…….38 Figure 1.12: Dorsal view of the Champsosaurus type specimen, AMNH FR 5696 (Champsosaurus sp.)…………………………………………………………………….47 Figure 2.1: Articulated skull of Champsosaurus lindoei (CMN 8920) in dorsal, ventral, and left lateral view………………………………………………………………………73 Figure 2.2: Articulated skull of Champsosaurus lindoei (CMN 8920) in anterior and posterior view…………………………………………………………………………….74 ix Figure 2.3: Major skull openings of Champsosaurus lindoei (CMN 8920)……………..75 Figure 2.4: Skull measurements for Champsosaurus lindoei (CMN 8920)……………..76 Figure 2.5: Isolated premaxilla and maxilla of Champsosaurus lindoei (CMN 8920)….77 Figure 2.6: Isolated nasal and lacrimal of Champsosaurus lindoei (CMN 8920)……….81 Figure 2.7: Isolated prefrontals and frontals of Champsosaurus lindoei (CMN 8920)….83 Figure 2.8: Isolated postfrontal and postorbital of Champsosaurus lindoei (CMN 8920)……………………………………………………………………………………..86 Figure 2.9: Isolated parietals of Champsosaurus lindoei (CMN 8920)………………….87 Figure 2.10: Isolated left neomorphic bone of Champsosaurus lindoei (CMN 8920)…..90 Figure 2.11: Isolated jugal, quadratojugal, and squamosal
Load more

Recommended publications
  • Six Adventure Road Trips
    Easy Drives, Big Fun, and Planning Tips Six Adventure Road Trips DAY HIKES, FLY-FISHING, SKIING, HISTORIC SITES, AND MUCH MORE A custom guidebook in partnership with Montana Offi ce of Tourism and Business Development and Outside Magazine Montana Contents is the perfect place for road tripping. There are 3 Glacier Country miles and miles of open roads. The landscape is stunning and varied. And its towns are welcoming 6 Roaming the National Forests and alluring, with imaginative hotels, restaurants, and breweries operated by friendly locals. 8 Montana’s Mountain Yellowstone and Glacier National Parks are Biking Paradise the crown jewels, but the Big Sky state is filled with hundreds of equally awesome playgrounds 10 in which to mountain bike, trail run, hike, raft, Gateways to Yellowstone fish, horseback ride, and learn about the region’s rich history, dating back to the days of the 14 The Beauty of Little dinosaurs. And that’s just in summer. Come Bighorn Country winter, the state turns into a wonderland. The skiing and snowboarding are world-class, and the 16 Exploring Missouri state offers up everything from snowshoeing River Country and cross-country skiing to snowmobiling and hot springs. Among Montana’s star attractions 18 Montana on Tap are ten national forests, hundreds of streams, tons of state parks, and historic monuments like 20 Adventure Base Camps Little Bighorn Battlefield and the Lewis and Clark National Historic Trail. Whether it’s a family- 22 friendly hike or a peaceful river trip, there’s an Montana in Winter experience that will recharge your spirit around every corner in Montana.
    [Show full text]
  • Status of Mineral Resource Information for the Fort Berthold Indian Reservation, North Dakota
    STATUS OF MINERAL RESOURCE INFORMATION FOR THE FORT BERTHOLD INDIAN RESERVATION, NORTH DAKOTA By Bradford B. Williams Mary E. Bluemle U.S. Bureau of Mines N. Dak. Geological Survey Administrative report BIA-40 1978 CONTENTS SUMMARY AND CONCLUSIONS ................................................. 1 INTRODUCTION ................................................................ 1 Area Location and Access .................................................... 1 Past Investigations .......................................................... 2 Present Study and Acknowledgments ........................................... 2 Land Status................................................................ 2 Physiography .............................................................. 3 GEOLOGY ..................................................................... 4 Stratigraphy ............................................................... 4 Subsurface .......................................................... 4 Surface ............................................................. 4 General ....................................................... 4 Bullion Creek and Sentinel Butte Formations ......................... 8 Golden Valley Formation......................................... 9 Cole Harbor Formation .......................................... 9 Structure................................................................. 10 MINERAL RESOURCES ......................................................... 11 General .................................................................
    [Show full text]
  • The Transition from the Judith River Formation to the Bearpaw Shale
    The transition from the Judith River Formation to the Bearpaw Shale (Campanian), north-central Montana by Roger Elmer Braun A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Earth Sciences Montana State University © Copyright by Roger Elmer Braun (1983) Abstract: The upper 15 m of the Judith River Formation on and adjacent to the Fort Belknap Indian Reservation, north-central Montana is composed mostly of overbank mudrock, siltstone, fine-grained sandstone, and coal, with some cross-stratified channel sandstone in the lower part. The lower 15 m of the overlying Bearpaw Shale is a transgressive deposit composed primarily of concretionary silty shale with some clayey, silty sandstone zones and one bentonite bed. The source area for both formations was primarily in western Montana and Idaho, with the Elkhorn Mountains volcanics a major source of debris. The contact between the Judith River and Bearpaw formations is abrupt and lacks a transgressive sandstone facies. The transgression of the Bearpaw sea across the study area is considered to have been a nearly isochronous event because of the nature of the transition, small east-west differences in thickness between marker horizons, and similar elevations of the contact from east to west across undeformed parts of the study area. The Bearpaw transgression was caused mainly by tectonic thickening in the western Cordillera, which created subsidence primarily in the western and central portions of the Western Interior basin. The transgression was a nearly isochronous event that took place approximately 72 m.y. ago according to radiometric age dates on bentonite beds.
    [Show full text]
  • Stem Caecilian from the Triassic of Colorado Sheds Light on the Origins
    Stem caecilian from the Triassic of Colorado sheds light PNAS PLUS on the origins of Lissamphibia Jason D. Pardoa, Bryan J. Smallb, and Adam K. Huttenlockerc,1 aDepartment of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1; bMuseum of Texas Tech University, Lubbock, TX 79415; and cDepartment of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089 Edited by Neil H. Shubin, The University of Chicago, Chicago, IL, and approved May 18, 2017 (received for review April 26, 2017) The origin of the limbless caecilians remains a lasting question in other early tetrapods; “-ophis” (Greek) meaning serpent. The vertebrate evolution. Molecular phylogenies and morphology species name honors paleontologist Farish Jenkins, whose work on support that caecilians are the sister taxon of batrachians (frogs the Jurassic Eocaecilia inspired the present study. and salamanders), from which they diverged no later than the early Permian. Although recent efforts have discovered new, early Holotype. Denver Museum of Nature & Science (DMNH) 56658, members of the batrachian lineage, the record of pre-Cretaceous partial skull with lower jaw and disarticulated postcrania (Fig. 1 caecilians is limited to a single species, Eocaecilia micropodia. The A–D). Discovered by B.J.S. in 1999 in the Upper Triassic Chinle position of Eocaecilia within tetrapod phylogeny is controversial, Formation (“red siltstone” member), Main Elk Creek locality, as it already acquired the specialized morphology that character- Garfield County, Colorado (DMNH loc. 1306). The tetrapod as- izes modern caecilians by the Jurassic. Here, we report on a small semblage is regarded as middle–late Norian in age (Revueltian land amphibian from the Upper Triassic of Colorado, United States, with vertebrate faunachron) (13).
    [Show full text]
  • Theodore Roosevelt National Park Geologic Resource Evaluation Report
    National Park Service U.S. Department of the Interior Natural Resource Program Center Theodore Roosevelt National Park Geologic Resource Evaluation Report Natural Resource Report NPS/NRPC/GRD/NRR—2007/006 THIS PAGE: The Little Missouri River flows near the Juniper Campground in the North Unit of Theodore Roosevelt NP, ND. ON THE COVER: View from the Oxbow Overlook Theodore Roosevelt NP, ND. Photos by: Dave Krueger Theodore Roosevelt National Park Geologic Resource Evaluation Report Natural Resource Report NPS/WASO/NRPC/GRD—2007/006 Geologic Resources Division Natural Resource Program Center P.O. Box 25287 Lakewood, Colorado 80225 June 2007 U.S. Department of the Interior Washington, D.C. The Natural Resource Publication series addresses natural resource topics that are of interest and applicability to a broad readership in the National Park Service and to others in the management of natural resources, including the scientific community, the public, and the NPS conservation and environmental constituencies. Manuscripts are peer- reviewed to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and is designed and published in a professional manner. Natural Resource Reports are the designated medium for disseminating high priority, current natural resource management information with managerial application. The series targets a general, diverse audience, and may contain NPS policy considerations or address sensitive issues of management applicability. Examples of the diverse array of reports published in this series include vital signs monitoring plans; "how to" resource management papers; proceedings of resource management workshops or conferences; annual reports of resource programs or divisions of the Natural Resource Program Center; resource action plans; fact sheets; and regularly- published newsletters.
    [Show full text]
  • HOVASAURUS BOULEI, an AQUATIC EOSUCHIAN from the UPPER PERMIAN of MADAGASCAR by P.J
    99 Palaeont. afr., 24 (1981) HOVASAURUS BOULEI, AN AQUATIC EOSUCHIAN FROM THE UPPER PERMIAN OF MADAGASCAR by P.J. Currie Provincial Museum ofAlberta, Edmonton, Alberta, T5N OM6, Canada ABSTRACT HovasauTUs is the most specialized of four known genera of tangasaurid eosuchians, and is the most common vertebrate recovered from the Lower Sakamena Formation (Upper Per­ mian, Dzulfia n Standard Stage) of Madagascar. The tail is more than double the snout-vent length, and would have been used as a powerful swimming appendage. Ribs are pachyostotic in large animals. The pectoral girdle is low, but massively developed ventrally. The front limb would have been used for swimming and for direction control when swimming. Copious amounts of pebbles were swallowed for ballast. The hind limbs would have been efficient for terrestrial locomotion at maturity. The presence of long growth series for Ho vasaurus and the more terrestrial tan~saurid ThadeosauTUs presents a unique opportunity to study differences in growth strategies in two closely related Permian genera. At birth, the limbs were relatively much shorter in Ho vasaurus, but because of differences in growth rates, the limbs of Thadeosau­ rus are relatively shorter at maturity. It is suggested that immature specimens of Ho vasauTUs spent most of their time in the water, whereas adults spent more time on land for mating, lay­ ing eggs and/or range dispersal. Specilizations in the vertebrae and carpus indicate close re­ lationship between Youngina and the tangasaurids, but eliminate tangasaurids from consider­ ation as ancestors of other aquatic eosuchians, archosaurs or sauropterygians. CONTENTS Page ABREVIATIONS . ..... ... ......... .......... ... ......... ..... ... ..... .. .... 101 INTRODUCTION .
    [Show full text]
  • The Shoulder Girdle and Anterior Limb of Drepanosaurus Unguicaudatus
    <oological Journal of the Linnean Socieg (1994), Ill: 247-264. With 12 figures The shoulder girdle and anterior limb of Drepanosaurus unguicaudatus (Reptilia, Neodiapsida) from the upper Triassic (Norian) Downloaded from https://academic.oup.com/zoolinnean/article/111/3/247/2691415 by guest on 27 September 2021 of Northern Italy SILVIO RENESTO Dipartimento di Scienze della Terra, Universita degli Studi, Via Mangiagalli 34, I-20133 Milano, Italy Received January 1993, accepted for publication February 1994 A reinvestigation of the osteology of the holotype of Drepanosaurus unguicaudatus Pinna, 1980 suggests that in earlier descriptions some osteological features were misinterpreted, owing to the crushing of the bones and because taphonomic aspects were not considered. The pattern of the shoulder girdle and fore-limb was misunderstood: the supposed interclavicle is in fact the right scapula, and the bones previously identified as coracoid and scapula belong to the anterior limb. The new reconstruction of the shoulder girdle, along with the morphology of the phalanges and caudal vertebrae, leads to a new hypothesis about the mode oflife of this reptile. Drepanosaurus was probably an arboreal reptile which used its enormous claws to scrape the bark from trees, perhaps in search of insects, just as the modern pigmy anteater (Cyclopes) does. Available diagnostic characters place Drepanosaurus within the Neodiapsida Benton, but it is impossible to ascribe this genus to one or other of the two major neodiapsid lineages, the Archosauromorpha and the Lepidosauromorpha. ADDITIONAL KEY WORDS:-Functional morphology - taxonomy - taphonomy - palaeoecology . CONTENTS Introduction ................... 247 Taphonomy ..... .............. 249 Systematic palaeontology . .............. 251 Genus Drepanosaurus Pinna, 1980 .............. 252 Drepannsaurus unguicaudatus Pinna, 1980.
    [Show full text]
  • The First Possible Choristoderan Trackway from the Lower
    www.nature.com/scientificreports OPEN The frst possible choristoderan trackway from the Lower Cretaceous Daegu Formation of South Korea and its implications on choristoderan locomotion Yuong‑Nam Lee1*, Dal‑Yong Kong2 & Seung‑Ho Jung2 Here we report a new quadrupedal trackway found in the Lower Cretaceous Daegu Formation (Albian) in the vicinity of Ulsan Metropolitan City, South Korea, in 2018. A total of nine manus‑pes imprints show a strong heteropodous quadrupedal trackway (length ratio is 1:3.36). Both manus and pes tracks are pentadactyl with claw marks. The manus prints rotate distinctly outward while the pes prints are nearly parallel to the direction of travel. The functional axis in manus and pes imprints suggests that the trackmaker moved along the medial side during the stroke progressions (entaxonic), indicating weight support on the inner side of the limbs. There is an indication of webbing between the pedal digits. These new tracks are assigned to Novapes ulsanensis, n. ichnogen., n. ichnosp., which are well‑matched not only with foot skeletons and body size of Monjurosuchus but also the fossil record of choristoderes in East Asia, thereby N. ulsanensis could be made by a monjurosuchid‑like choristoderan and represent the frst possible choristoderan trackway from Asia. N. ulsanensis also suggests that semi‑aquatic choristoderans were capable of walking semi‑erect when moving on the ground with a similar locomotion pattern to that of crocodilians on land. South Korea has become globally famous for various tetrapod footprints from Cretaceous strata1, among which some clades such as frogs2, birds3 and mammals4 have been proved for their existences only with ichnological evidence.
    [Show full text]
  • (Diapsida: Saurosphargidae), with Implications for the Morphological Diversity and Phylogeny of the Group
    Geol. Mag.: page 1 of 21. c Cambridge University Press 2013 1 doi:10.1017/S001675681300023X A new species of Largocephalosaurus (Diapsida: Saurosphargidae), with implications for the morphological diversity and phylogeny of the group ∗ CHUN LI †, DA-YONG JIANG‡, LONG CHENG§, XIAO-CHUN WU†¶ & OLIVIER RIEPPEL ∗ Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, China ‡Department of Geology and Geological Museum, Peking University, Beijing 100871, PR China §Wuhan Institute of Geology and Mineral Resources, Wuhan, 430223, PR China ¶Canadian Museum of Nature, PO Box 3443, STN ‘D’, Ottawa, ON K1P 6P4, Canada Department of Geology, The Field Museum, 1400 S. Lake Shore Drive, Chicago, IL 60605-2496, USA (Received 31 July 2012; accepted 25 February 2013) Abstract – Largocephalosaurus polycarpon Cheng et al. 2012a was erected after the study of the skull and some parts of a skeleton and considered to be an eosauropterygian. Here we describe a new species of the genus, Largocephalosaurus qianensis, based on three specimens. The new species provides many anatomical details which were described only briefly or not at all in the type species, and clearly indicates that Largocephalosaurus is a saurosphargid. It differs from the type species mainly in having three premaxillary teeth, a very short retroarticular process, a large pineal foramen, two sacral vertebrae, and elongated small granular osteoderms mixed with some large ones along the lateral most side of the body. With additional information from the new species, we revise the diagnosis and the phylogenetic relationships of Largocephalosaurus and clarify a set of diagnostic features for the Saurosphargidae Li et al.
    [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]
  • United States
    DEPARTMENT OF THE INTERIOR BULLETIN OF THE UNITED STATES ISTo. 146 WASHINGTON GOVERNMENT Pit IN TING OFFICE 189C UNITED STATES GEOLOGICAL SURVEY CHAKLES D. WALCOTT, DI11ECTOK BIBLIOGRAPHY AND INDEX NORTH AMEEICAN GEOLOGY, PALEONTOLOGY, PETEOLOGT, AND MINERALOGY THE YEA.R 1895 FEED BOUGHTON WEEKS WASHINGTON Cr O V E U N M K N T P K 1 N T I N G OFFICE 1890 CONTENTS. Page. Letter of trail smittal...... ....................... .......................... 7 Introduction.............'................................................... 9 List of publications examined............................................... 11 Classified key to tlio index .......................................... ........ 15 Bibliography ............................................................... 21 Index....................................................................... 89 LETTER OF TRANSMITTAL DEPARTMENT OF THE INTEEIOE, UNITED STATES GEOLOGICAL SURVEY, DIVISION OF GEOLOGY, Washington, D. 0., June 23, 1896. SIR: I have the honor to transmit herewith the manuscript of a Bibliography and Index of North American Geology, Paleontology, Petrology, and Mineralogy for the year 1895, and to request that it be published as a bulletin of the Survey. Very respectfully, F. B. WEEKS. Hon. CHARLES D. WALCOTT, Director United States Geological Survey. 1 BIBLIOGRAPHY AND INDEX OF NORTH AMERICAN GEOLOGY, PALEONTOLOGY, PETROLOGY, AND MINER­ ALOGY FOR THE YEAR 1895. By FRED BOUGHTON WEEKS. INTRODUCTION. The present work comprises a record of publications on North Ameri­ can geology, paleontology, petrology, and mineralogy for the year 1895. It is planned on the same lines as the previous bulletins (Nos. 130 and 135), excepting that abstracts appearing in regular periodicals have been omitted in this volume. Bibliography. The bibliography consists of full titles of separate papers, classified by authors, an abbreviated reference to the publica­ tion in which the paper is printed, and a brief summary of the con­ tents, each paper being numbered for index reference.
    [Show full text]
  • Tiago Rodrigues Simões
    Diapsid Phylogeny and the Origin and Early Evolution of Squamates by Tiago Rodrigues Simões A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in SYSTEMATICS AND EVOLUTION Department of Biological Sciences University of Alberta © Tiago Rodrigues Simões, 2018 ABSTRACT Squamate reptiles comprise over 10,000 living species and hundreds of fossil species of lizards, snakes and amphisbaenians, with their origins dating back at least as far back as the Middle Jurassic. Despite this enormous diversity and a long evolutionary history, numerous fundamental questions remain to be answered regarding the early evolution and origin of this major clade of tetrapods. Such long-standing issues include identifying the oldest fossil squamate, when exactly did squamates originate, and why morphological and molecular analyses of squamate evolution have strong disagreements on fundamental aspects of the squamate tree of life. Additionally, despite much debate, there is no existing consensus over the composition of the Lepidosauromorpha (the clade that includes squamates and their sister taxon, the Rhynchocephalia), making the squamate origin problem part of a broader and more complex reptile phylogeny issue. In this thesis, I provide a series of taxonomic, phylogenetic, biogeographic and morpho-functional contributions to shed light on these problems. I describe a new taxon that overwhelms previous hypothesis of iguanian biogeography and evolution in Gondwana (Gueragama sulamericana). I re-describe and assess the functional morphology of some of the oldest known articulated lizards in the world (Eichstaettisaurus schroederi and Ardeosaurus digitatellus), providing clues to the ancestry of geckoes, and the early evolution of their scansorial behaviour.
    [Show full text]