A Large and Robust Legless Lizard (Squamata, Anguinae) from the Gray Fossil Site of Eastern Tennessee

Abstract

The early Pliocene Gray Fossil Site in Tennessee preserved an abundance of microfossils, including numerous anguid lizard specimens. This includes the following elements: dentaries, a pterygoid fragment, a jugal, frontals, parietal fragments, dorsal and caudal vertebrae, and many osteoderms. Because these specimens had not been placed taxonomically beyond the subfamily level, comparative anatomy of similar elements from extant anguids and some quantitative data were used to provide more refined identifications. Using these methods, it was determined that a new, robust type of Ophisaurus is represented at the Gray Fossil Site. Important novel features include relatively robust dentaries, fewer but broader and more posteriorly recurved teeth, more extensive tooth placements on the pterygoid, and more extensive rugosities on the jugal, parietal and frontal. This new anguid’s identification provides a more thorough understanding of this region’s ecosystems during a relatively unknown period in Appalachian prehistory.