Osteopygis is a genus of extinct turtle. Osteopygis, as traditionally seen, is a chimera: the postcrania (including the holotype) belong to a non-marine stem-cryptodire, whilst the crania belong to sea turtles. In 2005, the referred material was split between two taxa: the postcrania remained in Osteopygis, while the crania were reassigned to Euclastes wielandi.A reassessment of the referral of sea turtle skulls to the genus Osteopygis (Late Cretaceous, New Jersey, USA)
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