PHYLOGENETIC RELATIONSHIPS AND MORPHOLOGY OF TAPIRUS POLKENSIS (OLSEN) FROM THE LATE NEOGENE OF THE SOUTHEASTERN UNITED STATES

The most abundant mammal at the Gray Fossil Site in eastern Tennessee is a small-sized species of Tapirus. Morphologic and statistical comparisons of the Gray tapir sample with specimens of “Tapiravus” polkensis Olsen, 1960 from the late Miocene and early Pliocene (Hemphillian) of central Florida find no significant differences and the two are regarded as conspecific. These comparisons also indicate that the holotype of T. polkensis, an isolated upper premolar, is not a P4, as originally identified, but is instead a P3. Cladistic analysis of 10 extinct and 4 extant tapirids with 64 parsimony informative characters reveals strong support for a monophyletic Tapirus that includes T. polkensis, and that T. polkensis is a member of a clade that also includes Tapirus bairdii, T. haysii, and T. veroensis.