aInstituto de Geociências, Programa de Pós-Graduação em Geociências, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves, 9500, Campus do Vale, CEP 91501-970, Porto Alegre, Rio Grande do Sul, Brazil email@example.com
bSeção de Paleontologia, Museu de Ciências Naturais, Fundação Zoobotânica do Rio Grande do Sul, Avenida Dr. Salvador França, 1427, Jardim Botânico, CEP 90690-000, Porto Alegre, Rio Grande do Sul, Brazil
A new species of Tapirus (Perissodactyla: Tapiridae) is described from the upper Pleistocene of the Rio Madeira Formation in Araras, Nova Mamoré Municipality, Rondonia State, Brazil. Tapirus rondoniensis sp. nov. is represented by a nearly complete skull with a unique combination of characters that differ from those of extant and fossil species of Tapirus described from South America. It is diagnosed mainly by its broad frontals that bear a pneumatization extending to the frontoparietal suture, a high sagittal crest, a weakly molarized P2 lacking a protoloph, and a metaloph that merely reaches the base of the ectoloph. T. rondoniensis sp. nov. is similar in some respects to T. terrestris, but it retains some primitive dental and cranial character states in common with T. pinchaque, such as broad frontals and a weakly molarized P2.