The type specimens of Tapivarus validus and Tapivarus rarus (Mammalia, Perissodactyla), with a review of the genus, and a new report of Miotapirus (Miotapirus marslandensis Schoch and Prins, new species) from Nebraska
Tapiravus Marsh, 1877, is a tapirid genus known from the middle Miocene to early Pliocene of New Jersey, Maryland, Florida and Nebraska. Three species have been referred to Tapiravus: T. validus (Marsh, 1871: the type species), T. rarus Marsh, 1877, and T. polkensis Olsen, 1960. In this paper the type specimens of T. validus and T. rarus are thoroughly described and illustrated for the first time. Additionally, all known specimens referable to the genus Tapiravus are listed. I conclude that Tapiravus is a valid genus composed of two recognizable species: T. validus and T. polkensis. The holotype and only known specimen of Tapiravus rarus is an isolated P3 which is not diagnostic at the specific level; thus the name Tapiravus rarus is best considered a nomen dubium. Finally, I report the first substantiated occurrence of Miotapirus, M. marslandensis Schoch and Prins, new species, from the early Miocene of Nebraska. M. marslandensis is based on two upper molars which are slightly larger than the corresponding teeth of M. harrisonensis.