Identification of Mosasaur (Squamata: Mosasauridae) from the Weskan Shale Member of Western Kansas

Abstract

By Justin Mays, Biological Sciences

Advisor: Takuya Konishi

Presentation ID: PM_ATRIUM03

Abstract: Mosasaurs are an extinct group of large, marine reptiles which lived during the Cretaceous Period. Their remains can be found worldwide, thus indicating a high degree of adaptability to various marine environments and trophic structures. Numerous mosasaur remains have been discovered throughout Kansas and the US Midwest, including the discovery of KUVP 155838 in 1930 by a geological survey field party from the University of Kansas. The remains were found in part of the Weskan Shale Member of the Pierre Shale Formation and include teeth, ribs, vertebrae, jaw fragments, and limb elements. Initially these remains were identified informally as Mosasaurus sp., but comparative review of the specimen suggests that it may pertain to a different genus. In particular, the teeth and jaws of this mosasaur exhibit heterodonty more comparable to that of the genus Prognathodon. Premaxillary and maxillary components show a more robust nature than that of Mosasaurus, further suggesting the specimen's affinity to Prognathodon. Additionally, podial elements such as the phalanges and the radius suggest a more elongated, slender paddle morphology consistent with Prognathodon and Clidastes, but not with Mosasaurus. This specimen being that of Prognathodon would make KUVP 155838 the first of its genus to be discovered in Kansas.