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Tylosaurus kansasensis, a new species of tylosaurine (Squamata, Mosasauridae) from the Niobrara Chalk of western Kansas, USA

Published online by Cambridge University Press:  01 April 2016

M.J. Everhart*
Affiliation:
Sternberg Museum of Natural History, Fort Hays State University, Hays, Kansas 67601, USA. Email: meverhar@fhsu.edu
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Abstract

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Tylosaurus kansasensis sp. nov. is described herein on the basis of thirteen specimens collected from the Smoky Hill Chalk (upper Coniacian) of western Kansas, USA. The new species, originally designated Tylosaurus n. sp., co-occurred with T. nepaeolicus and exhibits a number of primitive characters that place it in a basal position in the mosasaur phylogeny. Among the key differences separating this species from other tylosaurines are a shortened, more rounded pre-dental process of the premaxilla, a distinctive quadrate lacking an infrastapedial process, and a parietal foramen located adjacent to the frontal-parietal suture.

Type
Research Article
Copyright
Copyright © Stichting Netherlands Journal of Geosciences 2005

References

Bell, G.L. Jr., 1993. A phylogenetic revision of Mosasauroidea. University of Texas at Austin (Austin): 293 pp. (unpubl. PhD thesis).Google Scholar
Bell, G.L. Jr., 1997. A phylogenetic revision of North American and Adriatic Mosasauroidea. In: Callaway, J.M. & Nicholls, E.L. (eds): Ancient marine reptiles. Academic Press (San Diego): 293–332.Google Scholar
Cope, E.D., 1869. (Remarks on Macrosaurus proriger). Proceedings of the Academy of Natural Sciences of Philadelphia 11(81): 123.Google Scholar
Cope, E.D., 1870. Synopsis of the extinct Batrachia and Reptilia of North America. Transactions of the American Philosophical Society n.s. 14: 1–252 + i–viii.Google Scholar
Cope, E.D., 1872. (Remarks on discoveries recently made by Prof. 0. C. Marsh). Proceedings of the Academy of Natural Sciences of Philadelphia 24: 140–141.Google Scholar
Cope, E.D., 1874. Review of the Vertebrata of the Cretaceous period found west of the Mississippi River. United States Geological Survey of the Territories, Bulletin 1(2): 3–48.Google Scholar
Cope, E.D., 1875. The Vertebrata of the Cretaceous formations of the West. Report of the United States Geological Survey of the Territories (Hayden) 2: 302 pp.Google Scholar
Everhart, M.J., 2001. Revisions to the biostratigraphy of the Mosasauridae (Squamata) in the Smoky Hill Chalk Member of the Niobrara Chalk (Late Cretaceous) of Kansas. Transactions of the Kansas Academy of Science 104: 56–75.Google Scholar
Everhart, M.J., 2002. New data on cranial measurements and body length of the mosasaur, Tylosaurus nepaeolicus (Squamata; Mosasauridae), from the Niobrara Formation of western Kansas. Transactions of the Kansas Academy of Science 105: 33–43.Google Scholar
Everhart, M.J., 2004. Late Cretaceous interaction between predators and prey. Evidence of feeding by two species of shark on a mosasaur. PalArch 1: 1–7.Google Scholar
Everhart, M.J. & Everhart, P.A., 1997. Earliest occurrence of the mosasaur, Tylosaurus proriger (Mosasauridae: Squamata) in the Smoky Hill Chalk (Niobrara Formation, Upper Cretaceous) of western Kansas. Journal of Vertebrate Paleontology 17 (Suppl. to 3): 44A.Google Scholar
Hattin, D.E., 1982. Stratigraphy and depositional environment of the Smoky Hill Chalk Member, Niobrara Chalk (Upper Cretaceous) of the type area, western Kansas. Kansas Geological Survey, Bulletin 225: 1–108.Google Scholar
Leidy, J., 1873. Contributions to the extinct vertebrate fauna of the western interior territories. Report of the United States Geological Survey of the Territories (Hayden) 1: 358 pp.Google Scholar
Marsh, O.C., 1872a. On the structure of the skull and limbs in mosasaurid reptiles, with descriptions of new genera and species. American Journal of Science 3(18): 448–464.Google Scholar
Marsh, O.C., 1872b. Note on Rhinosaurus. American Journal of Science 4(20): 147.Google Scholar
Merriam, J.C., 1894. Ueber die Pythonomorphen der Kansas-kreide. Palaeontographica 41: 1–39.Google Scholar
Novas, F.E., Fernández, M., Gasparini, Z.B., Lirio, J.M., Nuňez, H.J. & Puerta, P., 2002. Lakumasaurus antarcticus, n. gen. et sp., a new mosasaur (Reptilia, Squamata) from the Upper Cretaceous of Antarctica. Ameghiniana 39: 245–249.Google Scholar
Russell, D.A., 1967. Systematics and morphology of American mosasaurs (Reptilia, Sauria). Bulletin of the Peabody Museum of Natural History, Yale University 23: 1–241.Google Scholar
Schumacher, B.A., 1993. Biostratigraphy of Mosasauridae (Squamata, Varanoidea) from the Smoky Hill Chalk Member, Niobrara Chalk (Upper Cretaceous) of western Kansas. Fort Hays State University (Hays, Kansas): 68 pp. (unpubl. MSc thesis).Google Scholar
Sheldon, M.A., 1996. Stratigraphie distribution of mosasaurs in the Niobrara Formation of Kansas. Paludicola 1: 21–31.Google Scholar
Stewart, J.D., 1990. Niobrara Formation vertebrate stratigraphy. In: Bennett, S.C. (ed.): Niobrara Chalk Excursion Guidebook. University of Kansas Museum of Natural History and Kansas Geological Survey: 19–30.Google Scholar
Williston, S.W., 1898. Mosasaurs. University Geological Survey of Kansas 4: 83–221.Google Scholar