Advertisement

Paläontologische Zeitschrift

, Volume 72, Issue 1–2, pp 149–162 | Cite as

New finds ofOmphalosaurus and a review of Triassic ichthyosaur paleobiogeography

  • P. Martin Sander
  • Christiane Faber
Article

Abstract

Triassic ichthyosaurs are very widespread and diverse but most taxa are poorly known. New discoveries, such as described in this paper, underscore the first statement but only slowy invalidate the second.

The first associated skeleton of the unusual durophagous ichthyosaurOmphalosaurus (O. wolfi) is reported from the Middle Triassic (earliest Ladinian) of the northern Alps. The vertebrae are of the ichthyosaurian type, firmly establishing the ichthyosaurian affinities of the genus.

A round bone from the Muschelkalk of Franconia, Germany, is identified and described as a left humerus ofOmphalosaurus sp. These finds greatly extend the paleogeographic and temporal range ofOmphalosaurus which previously was only known from the western cratonic margin of North America and from Spitsbergen. The new records ofOmphalosaurus allow a revised differential diagnosis of the genus and a revision of its species. Valid species ofOmphalosaurus areO. nettarhynchus, O. nevadanus, andO. wolfi.

In conjunction with such new insights into Triassic ichthyosaur distribution, it is necessary to address the validity of the poorly known genera such as the Middle TriassicPessosaurus. This taxon must be considered invalid because it lacks diagnostic characters.

In assessing progress in research on Triassic ichthyosaurs and their paleobiogeography, it becomes apparent that supra-specific diversity appears largely known, at least for the pre-Norian record of North America, Europe, and East Asia.

Keywords

Middle Triassic Lower Triassic Vertebrate Paleontology Martin Sander Nomen Dubium 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Kurzfassung

Triassische Ichthyosaurier sind weit verbreitet und sehr vielgestaltig, aber die meisten Formen sind schlecht bekannt. Neue Funde, wie sie hier beschrieben werden, unterstreichen die erste Feststellung, lassen die zweite aber nur langsam ungültig werden.

Das erste assoziierte Skelett des ungewöhnlichen durophagen IchthyosauriersOmphalosaurus, O. wolfi aus der Mitteltrias (unterstes Ladin) der Salzburger Alpen, wird beschrieben und diskutiert. Die Wirbel haben die für Ichthyosaurier typische Morphologie und belegen damit eindeutig die Zugehörigkeit dieses Taxons zu den Ichthyosauriern.

Ein runder Knochen aus dem fränkischen Muschelkalk wird als linker Humérus vonOmphalosaurus sp. identifiziert. Diese beiden Funde weiten das Verbreitungsgebiet und das zeitliche Auftreten vonOmphalosaurus bedeutend aus, da die Gattung bis jetzt nur vom Westrand des nordamerikanischen Kratons und von Spitzbergen bekannt war. Die neuen Funde erlauben außerdem eine Differentialdiagnose der Gattung und eine Revision ihrer Arten, von denenOmphalosaurus nettarhynchus, O. nevadanus undO. wolfi als gültig erachtet werden, nicht aberO. nisseri.

Im Zusammenhang mit diesen neuen Einsichten zur Verbreitung triassischer Ichthyosaurier ist es nötig, die Gültigkeit schlecht bekannter Gattungen, z.B. des mitteltriassischenPessosaurus, zu überprüfen.Pessosaurus ist kein valides Taxon, weil ihm diagnostische Merkmale fehlen.

Wenn man den Fortschritt in der Erforschung der Trias-Ichthyosaurier bewertet, stellt man fest, daß die Diversität auf dem Gattungs- und Familienniveau weitgehend bekannt ist, zumindest was prä-norische Vorkommen in Nordamerika, Europa und Ostasien betrifft.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Brinkman, D. B.;Nicholls, E. L. &Callaway, J. M. 1992a. New material of the ichthyosaur Mixosaurus nordenskioeldii from the Triassic of British Columbia, and the interspecific relationships of Mixosaurus. - North American Paleontological Convention V, Abstracts with Program: 37, Chicago.Google Scholar
  2. Brinkman, D. B.;Xijin, Z. &Nicholls, E. L. 1992b. A primitive ichthyosaur from the Lower Triassic of Brithish Columbia, Canada. - Palaeontology35: 465–474, Lawrence.Google Scholar
  3. Buffrénil, V. de &Mazin, J.-M. 1990. Bone histology of the ichthyosaurs: comparative data and functional interpretation. - Paleobiology16: 435–447, Lawrence.Google Scholar
  4. Buffrénil, V. de;Mazin, J. M. &Ricqlès, A. de 1987. Caractères structuraux et mode de croissance du fémur d’Omphalosaurus nisseri, Ichthyosaurien du Trias moyen de Spitsberg.- Annales de Paléontologie73: 195–216, Paris.Google Scholar
  5. Callaway, J. M. &Brinkman, D. B. 1989. Ichthyosaurs (Reptilia, Ichthyosauria) from the Lower and Middle Triassic Sulphur Mountain Formation, Wapiti Lake area, British Columbia, Canada. - Canadian Journal of Earth Science26: 1491–1500, Ottawa.Google Scholar
  6. Callaway, J. M. &Massare, J. A. 1989a. Geographic and stratigraphic distribution of the Triassic Ichthyosauria (Reptilia; Diapsida). - Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen178: 37–58, Stuttgart.Google Scholar
  7. — 1989b. Shastasaurus altispinus (Ichthyosauria, Shastasauridae) from the Upper Triassic of the El Antimonio district, northwestern Sonora, Mexico. - Journal of Paleontology63: 930–939, Lawrence.Google Scholar
  8. Camp, C. L. 1976. Vorläufige Mitteilung über große Ichthyosaurier aus der oberen Trias von Nevada. -Österreichische Akademie der Wissenschaften, Mathematisch-Naturwis-senschaftliche Klasse, Sitzungsberichte, (I)185: 125–134, Wien.Google Scholar
  9. — 1980. Large ichthyosaurs from the Upper Triassic of Nevada. - Palaeontographica, (A)170: 139–200, Stuttgart.Google Scholar
  10. Cook, D. H. N. 1994. A new ichthyosaur genus from the Middle Triassic of Monte San Giorgio, Switzerland (Abstract).-Journal of Vertebrate Paleontology14: 21A-22A, Lawrence.Google Scholar
  11. Coombs, W. P. &Deméré, T. A. 1995. A Late Cretaceous nodosaurid ankylosaur (Dinosauria: Ornithischia) from marine sediments of coastal California. - Journal of Paleontology70: 311–326, Lawrence.Google Scholar
  12. Dal Sasso, C. &,Pinna, G. 1996. Besanosaurus leptorhynchus n. gen. n. sp., a new shastasaurid ichthyosaur from the Middle Triassic of Besano (Lombardy, N. Italy). - Paleontologia Lombarda, Nuova serie4: 1–23, Milano.Google Scholar
  13. Hagdorn, H. 1991. Muschelkalk — A Field Guide. - 80 pp., Korb (Goldschneck-Verlag).Google Scholar
  14. Huene, F. von 1916. Beiträge zur Kenntnis der Ichthyosaurier im deutschen Muschelkalk. - Palaeontographica62: 1–68, Stuttgart.Google Scholar
  15. Hulke, I. W. 1873. Memorandum on some fossil vertebrate remains collected by the Swedish expeditions to Spitzbergen in 1864 and 1868. - Bihang till K. Svenska Vetenskapsakademiens Handlingar1: 1–11, Stockholm.Google Scholar
  16. Massare, J. A. &Callaway, J. M. 1994. Cymbospondylus (Ichthyosauria: Shastasauridae) from the Lower Triassic Thaynes Formation of southeastern Idaho. - Journal of Vertebrate Palaeontology14: 139–141, Lawrence.Google Scholar
  17. Mazin, J.-M. 1981a. Grippia longirostris Wiman, 1929, un Ichthyopterygia primitif du Trias inférieur du Spitsberg. -Bulletin du Muséum national d’Histoire naturelle, Paris3: 317–340, Paris.Google Scholar
  18. — 1981b. Svalbardosaurus crassidens n. g. n. sp., un Ichthyopterygien nouveau du Spathien (Trias inférieur) du Spitsberg. - Comptes Rendus de l’Académie des Sciences, Paris, (II)293: 111–113, Paris.Google Scholar
  19. — 1983. Omphalosaurus nisseri (Wiman, 1910), un ichthyoptérygien à denture broyeuse du Trias moyen du Spitsberg. - Bulletin du Muséum national d’Histoire naturelle, Paris5: 243–263, Paris.Google Scholar
  20. — 1984. Les Ichthyopterygia du Trias du Spitsberg — Descriptions complémentaires à partir d’un nouveau matériel. - Bulletin du Muséum national d’Histoire naturelle, Paris6: 309–320, Paris.Google Scholar
  21. — 1985. Les Ichthyopterygia du Trias supérieur de Nouvelle Calédonie. Implications paléobiogéographiques. - Revue de Paléobiologie4: 177–182, Geneva.Google Scholar
  22. — 1986a. A new interpretation of the type specimen of Omphalosaurus nevadanus Merriam 1906. -Palaeontographica, (A)195: 19–27, Stuttgart.Google Scholar
  23. — 1986b. Paleobiogeography of Triassic ichthyopterygian reptiles; some working hypotheses. - Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen173: 117–129, Stuttgart.Google Scholar
  24. Mazin, J.-M. &Bucher, H. 1987. Omphalosaurus nettarhynchus, une nouvelle espèce d’Omphalosauridé (Reptilia, Ichthyopterygia) du Spathien de la Humboldt Range (Nevada, U.S.A.). - Comptes Rendus de l’Académie des Sciences, Paris, (II)305: 823–828, Paris.Google Scholar
  25. Mazin, J.-M.;Suteethorn, V.;Buffetaut, E.;Jaeger, J.-J. &Helmcke-Ingavat, R. 1991. Preliminary descriptions of Thaisaurus chonglakmanii n.g. n.sp., a new ichthyopterygian from the Lower Triassic of Thailand. - Comptes Rendus de l’Académie des Sciences, Paris, (II)313: 1207–1212, Paris.Google Scholar
  26. McGowan, C. 1991. An ichthyosaur forefin from the Triassic of Brithish Columbia exemplifying Jurassic features. - Canadian Journal of Earth Sciences28: 1553–1560, Ottawa.Google Scholar
  27. — 1994. A new species of Shastasaurus (Reptilia: Ichthyosauria) from the Triassic of British Columbia: the most complete exemplar of the genus. - Journal of Vertebrate Paleontology14: 168–179, Lawrence.Google Scholar
  28. — 1995. A remarkable small ichthyosaur from the Upper Triassic of British Columbia, representing a new genus and species. - Canadian Journal of Earth Sciences32: 292–303, Ottawa.Google Scholar
  29. — 1996. A new and typically Jurassic ichthyosaur from the Upper Triassic of British Columbia. - Canadian Journal of Earth Sciences33: 24–32, Ottawa.CrossRefGoogle Scholar
  30. — 1997. A transitional ichthyosaur fauna. - [In:]Callaway, J. M. &Nicholls, E. L. [eds.] Ancient Marine Reptiles: 61–80, San Diego (Academic Press).CrossRefGoogle Scholar
  31. Merriam, J. C. 1902. Triassic Ichthyopterygia from California and Nevada. - University of California Publications — Bulletin of the Department of Geology3: 63–108, Berkeley.Google Scholar
  32. — 1906. Preliminary note on a new marine reptile from the Middle Triassic of Nevada. - University of California Publications — Bulletin of the Department of Geology5: 5–79, Berkeley.Google Scholar
  33. — 1908. Triassic Ichthyosauria, with special reference to the American forms. - Memoirs of the University of California1: 1–155, Berkeley.Google Scholar
  34. — 1910. The skull and dentition of a primitive ichthyosaurian from the Middle Triassic. - University of California Publications — Bulletin of the Department of Geology5: 381–390, Berkeley.Google Scholar
  35. — 1911. Notes on the relationships of the marine saurian fauna described from the Triassic of Spitzbergen by Wiman. - University of California Publications — Bulletin of the Department of Geology6: 317–327, Berkeley.Google Scholar
  36. Merriam, J. C. &Bryant, H. C. 1911. Notes on the dentition of Omphalosaurus. - University of California Publications — Bulletin of the Department of Geology6: 329–332, Berkeley.Google Scholar
  37. Motani, R. 1994. Computer aided comparisons among Early Triassic ichthysosaurs reveals smaller taxonomic diversity than was believed. - Journal of Vertebrate Paleontology14: 39A, Lawrence.Google Scholar
  38. — 1997a. Phylogeny of the Ichthyosauria (Amniota: Reptilia) with special reference to Triassic forms. -Journal of Vertebrate Paleontology17: 66A, Lawrence.Google Scholar
  39. — 1997b. Redescription of the dentition of Grippia longirostris (Ichthyosauria) with a comparison with Utatsusaurus hataii. - Journal of Vertebrate Paleontology17: 39–44, Lawrence.Google Scholar
  40. — 1997c. Temporal and spatial distribution of tooth implantations in Ichthyosaurs. - [In:]Callaway, J. M. &Nicholls, E. L. [eds.] Ancient Marine Reptiles: 81–103, San Diego (Academic Press).CrossRefGoogle Scholar
  41. Nicholls, E. L. &Brinkman, D. B. 1993. A new specimen of Utatsusaurus (Reptilia: Ichthyosauria) from the Lower Triassic Sulphur Mountain Formation of British Columbia. - Canadian Journal of Earth Science30: 486–490, Ottawa.CrossRefGoogle Scholar
  42. — 1996. A new ichthyosaur from the Triassic Sulphur Mountain Formation of British Columbia. - [In:]Sarjeant, W. A. S. [ed.] Vertebrate fossils and the evolution of scientific concepts: 521–535, London (Gordon and Breach Publishers).Google Scholar
  43. Nicholls, E. L.; Brinkman, D. B. & Callaway, J. M. [in press]. New material of Phalarodon (Reptilia: Ichthyosauria) from the Triassic of British Columbia and its bearings on the interrelationships of mixosaurs. - Palaeontographica, (A), Stuttgart.Google Scholar
  44. Orr, W. N. 1986. A Norian (Late Triassic) ichthyosaur from the Martin Bridge Limestone, Wallowa Mountains, Oregon. - U.S. Geological Survey, Professional Paper1435: 41–47, Washington.Google Scholar
  45. Ricqlès, A. de 1989. Les mécanismes hétérochroniques dans le retour des tétrapodes au milieu aquatique. - Géobios, Mémoire Spécial12: 337–348, Lyon.CrossRefGoogle Scholar
  46. Sander, P. M. 1989. The large ichthyosaur Cymbospondylus buchseri, sp. nov., from the Middle Triassic of Monte San Giorgio (Switzerland), with a survey of the genus in Europe. - Journal of Vertebrate Paleontology9: 163–173, Lawrence.Google Scholar
  47. — 1992. Cymbospondylus (Shastasauridae: Ichthyosauria) from the Middle Triassic of Spitsbergen: filling a paleobiogeographic gap. - Journal of Paleontology66: 332–337, Lawrence.Google Scholar
  48. — 1996. The microstructure of reptilian tooth enamel: terminology, function, and phylogeny. - Habilitation Thesis, University of Bonn. - 191 pp., Bonn.Google Scholar
  49. — 1997. The paleobiogeography of Shastasaurus. - [In:]Callaway, J. M. &Nicholls, E. L. [eds.] Ancient Marine Reptiles: 17–43, San Diego (Academic Press).CrossRefGoogle Scholar
  50. - [in press]. Prismless enamel in amniotes: terminology, function, and evolution. - [In:] Teaford, M. F.; Ferguson, M. W. J. & Smith, M. M. [eds.] Development, Function and Evolution of Teeth: New York (Cambridge University Press).Google Scholar
  51. Sander, P. M. &Bucher, H. 1990. On the presence of Mixosaurus (Ichthyopterygia: Reptilia) in the Middle Triassic of Nevada. - Journal of Paleontology64: 161–164, Lawrence.Google Scholar
  52. Sander, P. M. &Mazin, J.-M. 1993. The paleobiogeography of Middle Triassic ichthyosaurs: The five major faunas. - Paleontologia Lombarda, Nuova série2: 145–152, Milano.Google Scholar
  53. Sander, P. M.;Rieppel, O.C. &Bucher, H. 1994. New marine vertebrate fauna from the Middle Triassic of Nevada. - Journal of Paleontology68: 676–680, Lawrence.Google Scholar
  54. —; 1997. A new pistosaurid (Reptilia: Sauropterygia) from the Middle Triassic of Nevada and its implications for the origin of plesiosaurs. -Journal of Vertebrate Paleontology17: 526–533, Lawrence.Google Scholar
  55. Tichy, G. 1995. Ein früher, durophager Ichthyosaurier (Omphalosauridae) aus der Mitteltrias der Alpen. -Geologisch-Paläontologische Mitteilungen Innsbruck20: 349–369, Innsbruck.Google Scholar
  56. Wiman, C. 1910. Ichthyosaurier aus der Trias Spitzbergens. - Bulletin of the Geological Institution of Upsala10: 124- 148, Upsala.Google Scholar
  57. — 1916. Notes on the marine Triassic reptile fauna of Spitzbergen. - University of California Publications — Bulletin of the Department of Geology10: 63–73, Berkeley.Google Scholar
  58. Yakolew, N. 1902. Neue Funde von Trias-Sauriern auf Spitzbergen. - Verhandlungen der Kaiserlichen Mineralogischen Gesellschaft, (2)40: 179–203, Petersburg.Google Scholar
  59. Young, C. C.;Liu, D. &Zhang, M. 1982. Ichthyosauria from Xizang Zhong. - Monograph on Mount Xixia, Bangma, Scientific Expeditions 1964: 350–355, Peking.Google Scholar

Copyright information

© E. Schweizerbart’sche Verlagsbuchhandlung 1998

Authors and Affiliations

  • P. Martin Sander
    • 1
  • Christiane Faber
    • 2
  1. 1.Institut für PaläontologieUniversität BonnBonnGermany
  2. 2.PressbaumAustria

Personalised recommendations