Platypterygius Huene, 1922 (Ichthyosauria, Ophthalmosauridae) from the Late Cretaceous of Texas, USA

A partial ichthyosaur skeleton is described from the Grayson Marl (Late Cretaceous: Early Cenomanian, ~97 Ma) from Tarrant County, Texas. Prior to this discovery, the Cretaceous record of Texas ichthyosaurs consisted of isolated vertebrae. The new specimen consists of a partial disarticulated skull and postcranial elements including a postfrontal, parietal, quadrate, angular, surangular, several teeth, and several vertebrae including the atlas-axis complex, coracoid, and articulated partial forelimb. The forelimb is diagnostic in having a zeugopodial element anterior to the radius, rectangular phalanges, and an intermedium that does not make contact with the humerus allowing referral to Platypterygius von Huene 1922. This occurrence is the youngest of that taxon in Texas and is consistent with late European occurrences of the genus Platypterygius. Thomas L. Adams. Roy M. Huffington Department of Earth Sciences, Southern Methodist University, Dallas, Texas 75275-0395 USA tladams@smu.edu Anthony R. Fiorillo. Museum of Nature and Science, P.O. Box 151469, Dallas, Texas 75315 USA Tfiorillo@natureandscience.org

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