A large dromaeosaurid from North Carolina

Abstract

During the Cretaceous period, North America was divided into two landmasses, the eastern Appalachia and western Laramidia. Recent research on several sites scattered across the eastern margin of North America has allowed for the analysis of vertebrate faunas from the once obscure terrestrial fossil record of Appalachia, revealing the landmass harbored a distinctive fauna composed of mostly relict forms. One geological unit that has produced a comparatively extensive record of terrestrial vertebrates, including non-avian dinosaurs, is the middle Campanian Tar Heel Formation of North Carolina. Here, the first definitive occurrence of a dromaeosaurid from the Tar Heel Formation is reported on the basis of a tooth from a fairly large member of that group. This tooth clusters with those of dromaeosaurine dromaeosaurids from the western United States and Canada in morphometric analysis, differing in morphology and size from other dromaeosaurid teeth from southeastern North America that have been assigned to saurornitholestines or considered indeterminate. The tooth described herein is intermediate in size between those of smaller dromaeosaurids like Saurornitholestes and gigantic forms like Dakotaraptor, filling the gap between larger- and smaller-bodied dromaeosaurids from the Late Cretaceous.