Juvenile Pleistocene tapir skull from Russells Reserve Cave, Bath County, Virginia: Implications for cold climate adaptations

摘要

A crushed, partial skull of a juvenile tapir was found with isolated post cranial elements and other fauna in Russells Reserve Cave (RRC), Bath County, Virginia. The cranium is undated but more than likely of late Pleistocene age. It possesses a complete deciduous premolar series and first permanent molars. The M2s have not yet erupted but are visible in the crypt. The RRC specimen is slightly older, ontogenetically, than the type specimen of Tapirus excelsus Simpson ( = T. vereoensis) which is probably one of the youngest specimens known. Based upon cranial characters, primarily the lack of a dorsal flange on the maxilla, presence of an interparietal bone, anteriorly ascending cheek tooth row, and lack of sagittal crest, the RRC specimen is referred to the extinct species, Tapirus vereoensis. The sizes of the teeth and morphology of P1 and P2 of the RRC specimen are also consistent with an assignment to T. veroensis. Tapirus pinchaque, the modern woolly tapir, is adapted to cold Andean environments; cladistics and paleoecological studies suggest that cold adaptation may have evolved a second time in T. veroensis.