NEW MARINE REPTILE REMAINS AND GREATLY EXPANDED DIVERSITY FROM THE LATE CRETACEOUS OF SOUTH CAROLINA

Despite two centuries of sporadic prospecting and research, the fossil marine reptile communities of the upper Cretaceous rocks of the South Carolina coastal plain have still not been thoroughly characterized. We greatly expand their known diversity with the study and description of one of the largest known relevant collections, consisting of over forty marine reptile teeth housed at the Mace Brown Museum of Natural History (Charleston SC) and hailing from the Campanian/Maastrichtian Donoho Creek and Peedee formations. Previous studies have confidently identified only turtles, indeterminate plesiosaurs, and the two mosasaurs, Tylosaurus and Prognathodon. Careful morphological scrutiny (involving traits like shape, serration, carinal angle, dental faceting) and application of morphometric data comparisons permit a number of taxa never before reported from the state to be identified from this collection. These include the first plesiosaur remains from the state diagnostic below ordinal level, (Elasmosauridae indet.), possible remains of Clidastes propython, and crowns from the genus Mosasaurus (including teeth likely from the gigantic apex predator M. hoffmanni). The collection also revealed several anomalous teeth assignable to no known species but resembling Prognathodon and “Liodon.” Therefore, while aspects of the fauna are typical and match expectations for the location and interval, others demonstrate how much work remains to be done, and point to promise of future discoveries in this poorly documented part of the fossil record.