Hostname: page-component-7479d7b7d-m9pkr Total loading time: 0 Render date: 2024-07-08T05:50:34.506Z Has data issue: false hasContentIssue false

Cranial osteology of the giant mosasaur Plesiotylosaurus (Squamata, Mosasauridae)

Published online by Cambridge University Press:  14 July 2015

Johan Lindgren*
Affiliation:
GeoBiosphere Science Centre, Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden Department of Integrative Biology and Museum of Paleontology, University of California, 1101 Valley Life Sciences Building, Berkeley, CA 94720, USA,

Abstract

Based on the type material and a new, virtually intact skull from the mid-Maastrichtian part (probably Tierra Loma Shale) of the Moreno Formation, San Joaquin Valley, central California, the cranial osteology of the enigmatic mosasaurine Plesiotylosaurus crassidens (Squamata, Mosasauridae) is here described in detail. Plesiotylosaurus is characterized by a protruding rostrum on the snout and mandibles, a wide and virtually unconstricted internarial bar, large and robust pterygoid teeth, and quadrates with distally fused suprastapedial and infrastapedial processes. Distinctly obtruding predental prows, along with a number of elaborate cranial features, suggest a morphological convergence with tylosaurine mosasaurs.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anderson, F. M. 1958. Upper Cretaceous of the Pacific Coast. The Geological Society of America Memoir 71, 378 p.Google Scholar
Bell, G. L. 1997. A phylogenetic revision of North American and Adriatic Mosasauroidea, p. 293332. In Callaway, J. M. and Nicholls, E. L. (eds.), Ancient Marine Reptiles, Academic Press, San Diego.CrossRefGoogle Scholar
Camp, C. L. 1942. California mosasaurs. Memoirs of the University of California, 13:168.Google Scholar
Camp, C. L. 1951. Plotosaurus, a new generic name for Kolposaurus Camp, preoccupied. Journal of Paleontology, 25:822.Google Scholar
Christiansen, P. and Bonde, N. 2002. A new species of gigantic mosasaur from the Late Cretaceous of Israel. Journal of Vertebrate Paleontology, 22:629644.CrossRefGoogle Scholar
Conybeare, W. D. 1822. Fossil crocodiles and other saurian animals, p. 284304. In Parkinson, J. (ed.), Outlines of Oryctology. An Introduction to the Study of Fossil Organic Remains; Especially of Those Found in the British Strata: Intended to Aid the Student in his Enquiries Respecting the Nature of Fossils, and their Connection with the Formation of the Earth vii. Printed for the author, London.Google Scholar
Cope, E. D. 1868. On new species of extinct reptiles. Proceedings of the Academy of Natural Sciences of Philadelphia, 20:181.Google Scholar
Dollo, L. 1889. Note sur les vertébrés récemment offerts au Musée de Bruxelles par M. Alfred Lemonnier. Bulletin de la Société Belge de Géologie, de Paléontologie et d'Hydrologie, 3:181182.Google Scholar
Dortangs, R. W., Schulp, A. S., Mulder, E. W. A., Jagt, J. W. M., Peeters, H. H. G., and De Graaf, D. T. 2002. A large new mosasaur from the Upper Cretaceous of The Netherlands. Netherlands Journal of Geosciences, 81:18.CrossRefGoogle Scholar
Fonseca-Riviera, C. 1997. Late Cretaceous-Early Tertiary Paleoceanography and Cyclic Sedimentation along the California Margin: Evidence from the Moreno Fm. Unpublished Ph.D. dissertation, Stanford University, 449 p.Google Scholar
Gervais, P. 1853. Observations relatives aux reptiles fossiles de France. Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences, 36:374377, 470-474.Google Scholar
Gilmore, C. W. 1912. A new mosasauroid reptile from the Cretaceous of Alabama. Proceedings of the United States National Museum, 41:479484.CrossRefGoogle Scholar
Hay, O. P. 1902. Bibliography and catalogue of the fossil Vertebrata of North America. Bulletin of the Geological Survey of the United States 179, 868 p.Google Scholar
Hesse, C. J. and Welles, S. P. 1936. The first record of a dinosaur from the West Coast. Science, 84:157158.CrossRefGoogle ScholarPubMed
Hilton, R. P. 2003. Dinosaurs and other Mesozoic Reptiles of California. University of California Press: Berkeley and Los Angeles, xxviii + 318 p.Google Scholar
Lindgren, J. 2005. Dental and vertebral morphology of the enigmatic mosasaur Dollosaurus (Reptilia, Mosasauridae) from the lower Campanian (Upper Cretaceous) of southern Sweden. Bulletin of the Geological Society of Denmark, 52:1725.CrossRefGoogle Scholar
Lindgren, J. 2007a. California mosasaurs II: The Maastrichtian Moreno Formation revisited. Second Mosasaur Meeting, Abstract Booklet and Field Guide. Sternberg Museum of Natural History, Hays, 25.Google Scholar
Lindgren, J. 2007b. First Halisaurus (Squamata: Mosasauridae) from the Pacific Coast of North America. PaleoBios, 27:4047.Google Scholar
Lindgren, J., Caldwell, M. W., and Jagt, J. W. M., 2008. New data on the postcranial anatomy of the California mosasaur Plotosaurus bennisoni (Camp, 1942) (Upper Cretaceous: Maastrichtian), and the taxonomic status of P. tuckeri (Camp, 1942). Journal of Vertebrate Paleontology 28:10431054.CrossRefGoogle Scholar
Lindgren, J., Jagt, J. W. M. and Caldwell, M. W. 2007. A fishy mosasaur: the axial skeleton of Plotosaurus (Reptilia, Squamata) reassessed. Lethaia, 40:153160.CrossRefGoogle Scholar
Lingham-Soliar, T. 1991. Predation in mosasaurs—a functional approach. Natural Structures: Principles, Strategies, and Models in Architecture and Nature. Second International Symposium. SFB, 230:169177.Google Scholar
Lingham-Soliar, T. 1992. The tylosaurine mosasaurs (Reptilia, Mosasauridae) from the Upper Cretaceous of Europe and Africa. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre, 62:171194.Google Scholar
Lingham-Soliar, T. 1998. Unusual death of a Cretaceous giant. Lethaia, 31:308310.CrossRefGoogle Scholar
Lingham-Soliar, T. and Nolf, D. 1990. The mosasaur Prognathodon (Reptilia, Mosasauridae) from the Upper Cretaceous of Belgium. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre 59 (for 1989):137190.Google Scholar
Marsh, O. C. 1869. Notice of some new mosasauroid reptiles from the Greensand of New Jersey. American Journal of Science and Arts, 48:392397.CrossRefGoogle Scholar
Marsh, O. C. 1872. Note on Rhinosaurus. American Journal of Science and Arts, Third Series, 4:147.Google Scholar
Martin, L. D. and Rothschild, B. M. 1989. Paleopathology and diving mosasaurs. American Scientist, 77:460467.Google Scholar
McGuire, D. J. 1988. Depositional framework of the Upper Cretaceous-Lower Tertiary Moreno Formation, central San Joaquin Basin, California, p. 173188. In Graham, S. A. (ed.), Studies of the Geology of San Joaquin Basin. Pacific Section, SEPM 60.Google Scholar
Oppel, M. 1811. Die Ordnungen, Familien, und Gattungen der Reptilien als Prodrom einer Naturgeschichte derselben. Joseph Lindauer, München, XII + 87 p.CrossRefGoogle Scholar
Owen, R. 1841. Odontography; or, a Treatise on the Comparative Anatomy of the Teeth; their Physiological Relations, Mode of Development, and Microscopic Structure, in the Vertebrate Animals. Volume 1. Text. Hippolyte Baillière: London, 113288.Google Scholar
Payne, M. B. 1951. Type Moreno Formation and overlying Eocene strata on the west side of the San Joaquin Valley, Fresno and Merced counties, California. California Division of Mines Special Report 9, 29 p.Google Scholar
Russell, D. A. 1967. Systematics and morphology of American mosasaurs (Reptilia, Sauria). Peabody Museum of Natural History, Yale University, Bulletin 23:1241.Google Scholar
Saul, L. R. 1983. Turritella zonation across the Cretaceous-Tertiary boundary, California. University of California Publications in Geological Sciences, 125:1165.Google Scholar
Schulp, A. S. 2006. On Maastricht mosasaurs. Publicaties van het Natuurhistorisch Genootschap in Limburg, Reeks XLV, aflevering 1. Stichting Natuurpublicaties Limburg: Maastricht, 140 p.Google Scholar
Schulp, A. S., Polcyn, M. J., Mateus, O., Jacobs, L. L., and Morais, M. L. 2008. A new species of Prognathodon (Squamata, Mosasauridae) from the Maastrichtian of Angola, and the affinities of the mosasaur genus Liodon. Proceedings of the Second Mosasaur Meeting, Fort Hays Studies Special Issue, 3:112.Google Scholar
Squires, R. L. and Saul, L. R. 2003. New Late Cretaceous (Campanian and Maastrichtian) marine gastropods from California. Journal of Paleontology, 77:5063.2.0.CO;2>CrossRefGoogle Scholar
Welles, S. P. and Gregg, D. R. 1971. Late Cretaceous marine reptiles of New Zealand. Records of the Canterbury Museum, 9:1111.Google Scholar
Williston, S. W. 1897. Range and distribution of the mosasaurs, with remarks on synonymy. Kansas University Quarterly, 6:177185.Google Scholar
Yakovlev, N. 1901. Restes d'un mosasaurien trouvés dans le Crétacé Supérieur du sud de la Russie. Izvestiya Geologicheskii Komitet, 20:507520.Google Scholar
Yang, D. 1983. A Study of the Pectoral and Pelvic Appendages of California Mosasaurs. Unpublished . , Fresno, 98 p.Google Scholar