New genus of tapir (Mammalia: Tapiridae) from the Arikareean (earliest Miocene) of the Texas Coastal Plain

Abstract

ABSTRACT The nearly complete dentition of the rare tapirid Miotapirus marslandensis was recovered from the recently discovered late Arikareean Toledo Bend Local Fauna, Newton County, Texas. The species was previously known from only two associated upper molars found near Marsland, Nebraska, in 1917. The Nebraska molars, together with the Toledo Bend material and additional specimens from the Monroe Creek Formation, South Dakota, share unique characters lacking from the genotypic species, Miotapirus harrisonensis Schlaikjer. The species from Texas, South Dakota, and Nebraska appears closely related to the rare Protapirus robustus Sinclair from the upper John Day Formation, Oregon, based on derived characters of the dentition. Miotapirus marslandensis and Protapirus robustus are here referred to Nexuotapirus, gen. nov. A review of all late Oligocene-early Miocene North American tapirids concludes that Protapirus validus Hatcher and Tanyops undens Marsh are junior synonyms of P. simplex Wortman and Earle.