Paläontologische Zeitschrift

, Volume 70, Issue 3–4, pp 579–589

Endocranial casts of early archosaurian reptiles

  • David J. Gower
  • Andrei G. Sennikov
Article

Abstract

The first endocranial casts from non-crown-group archosaurian reptiles are described. Synthetic casts were made of the preserved parts of the endocranial cavities ofErythrosuchus africanus,Vjushkovia triplicostata andXilousuchus sapingensis. These casts are incomplete, but they reveal a substantial amount of information on the form of the early archosaur brain and inner ear. Cranial and pontine flexures are equal in bothErythrosuchus (45°) andV. triplicostata (35–40°). The endocasts ofXilousuchus andV. triplicostata are characterised by the possession of a pseudolagena and a quantifiable down-slope from the myelencephalon to the metencephalon — features that have yet to be described for other reptilian endocranial casts.

Kurzfassung

Zum erstenmal werden Gehirnabgüsse sehr früher Archosaurier beschrieben. Morphologische Daten wurden an Exemplaren vonErythrosuchus africanus, Vjushkovia triplicostata undXilousuchus sapingensis gewonnen. Die teilweise unvollständigen Abgüsse liefern eine Anzahl von neuen Daten über die Gestaltung des Gehirnes und Innenohres früher Archosaurier. Die craniale und pontische Flexur haben jeweils gleiche Winkel inErythrosuchus (45°) andV. triplicostata (35–40°).Xilousuchus andV. triplicostata besitzen außerdem eine Pseudolagena und einen meßbaren Abstieg vom Myelencephalon zum Metencephalon — Merkmale, die von Gehirnabgüssen anderer Archosaurier noch unbekannt sind.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Benton, M. J. 1983. The Triassic reptileHyperodapedon from Elgin: functional morphology and relationships. -Philosophical Transactions of the Royal Society of London, (B)302: 605–720, London.CrossRefGoogle Scholar
  2. Benton, M. J. &Clark, J. M. 1988. Archosaur phylogeny and the relationships of the Crocodylia. - [In]Benton, M. J. (ed.). The phylogeny and classification of the tetrapods: 295–338, Oxford (Clarendon Press).Google Scholar
  3. Broom, R. 1905. Notice of some new fossil reptiles from the Karroo beds of South Africa. - Records of the Albany Museum1: 331–337, Grahamstown.Google Scholar
  4. Case, E. C. 1928. An endocranial cast of a phytosaur from the Upper Triassic beds of western Texas. - Journal of Comparative Neurology45: 161–168, Philadelphia.CrossRefGoogle Scholar
  5. Clark, J. M.;Welman, J.;Gauthier, J. A. &Parrish, J. M. 1993. The laterosphenoid bone of early archosauriforms. -Journal of Vertebrate Paleontology13: 48–57, Lawrence.Google Scholar
  6. Evans, S. E. 1986. The braincase ofProlacerta broomi (Reptilia, Triassic). - Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen173: 181–200, Stuttgart.Google Scholar
  7. Gauthier, J. A. 1986. Saurischian monophyly and the origin of birds. - Memoirs of the Californian Academy of Science8: 1–55, San Francisco.Google Scholar
  8. Giffin, E. B. 1989. Pachycephalosaur paleoneurology. - Journal of Venebrate Paleontology9: 67–77, Lawrence.Google Scholar
  9. Gow, C. E. 1975. The morphology and relationships ofYoungina capensis Broom andProlacerta broomi Parrington.- Palaeontologia africana18: 89–131, Johannesburg.Google Scholar
  10. Hopson, J. A. 1979. Paleoneurology. [In:]Gans, C.;Northcutt, R. C. &Ulinski, P. (eds.). Biology of the Reptilia9: 39–146, New York, London (Academic Press).Google Scholar
  11. Huene, F. von 1991. ÜberErythrosuchus, Vertreter der neuen Reptil-Ordnung Pelycosimia. - Geologische und Paläontologische Abhandlungen10: 67–122, Jena.Google Scholar
  12. — 1960. Ein grosser Pseudosuchier aus der Orenburger Trias. - Palaeontographica, (A)114: 105–111, Stuttgart.Google Scholar
  13. Parrish, J. M. 1993. Phylogeny of the Crocodylotarsi, with special reference to archosaurian and crurotarsan monophyly.-Journal of Vertebrate Paleontology13: 287–308, Lawrence.Google Scholar
  14. Säve-Söderbergh, G. 1946. On the fossa hypophyseos and the attachment of the retractor bulbi group inSphenodon, Varanus, andLacerta. - Arkiv för zoologi38A: 1–24, Stockholm.Google Scholar
  15. Senn, D. G. 1979. Embryonic development of the central nervous system. - [In:]Gans, C.;Northcutt, R.C. &Ulinski, P. (eds.). Biology of the Reptilia9: 173–244, New York, London (Academic Press).Google Scholar
  16. Sereno, P. C. 1991. Basal archosaurs: phylogenetic relationships and functional implications. - Society of Vertebrate Paleontology Memoir2: 1–53, Lawrence.CrossRefGoogle Scholar
  17. Tatarinov, L. P. 1961. Materialy po psevdozukhiyam SSSR. - Paleontologeskii Zhurnal2: 117–132, Moscow [In Russian].Google Scholar
  18. Walker, A.D. 1990. A revision ofSphenosuchus acutus Haughton, a crocodylomorph reptile from the Elliot Formation (late Triassic or early Jurassic) of South Africa. - Philosophical Transactions of the Royal Society of London, (B)330: 1–120, London.CrossRefGoogle Scholar
  19. Wu, X. 1981. The discovery of a new thecodont from north east Shanxi. - Vertebrata Palasiatica169: 122–132, Beijing [In Chinese].Google Scholar
  20. Young, C.C. 1973. On the occurence ofVjusbkovia in Sinkiang. - Memoirs of the Institute of Paleontology and Paleoanthropology, Academia Sinica10: 38–52, Beijing [In Chinese].Google Scholar

Copyright information

© E. Schweizerbart’sche Verlagsbuchhandlung 1996

Authors and Affiliations

  • David J. Gower
    • 1
    • 2
  • Andrei G. Sennikov
    • 3
  1. 1.Dept. of GeologyUniversity of BristolBristolUK
  2. 2.Geologisches InstitutUniversität TübingenTübingenGermany
  3. 3.Paleontological InstituteMoscowRussia

Personalised recommendations