Mammals of the Rhino Hill West Fauna, Miocene (Hemphillian), Wallace County, KS

Material from 13 different mammalian families was recovered from the Rhinoceros Hill West l.f., Miocene (Late Hemphillian), Wallace County, Kansas. Taxa identified to species include Osteoborus cyonoides (Martin). Vulpes cf. V. stenognathus Savage, ?Agriotherium schneideri Sellards, ?Pseudaelurus sp., Felis cf. F. proterolyncis, Savage, Nimravides cf. N. catocopis (Cope), Amebelodon sp., Astrohippus ansae Matthew and Stirton, Dinohippus interpolatus (Cope), Nannippus lenticularis (Cope). Neohipparion eurystyle (Cope). Teleoceras sp., Prosthennops cf. P. (Macrogens) graffhami Schultz and Martin, Alforjas taylori Harrison, Hemiauchenia vera (Matthew), and Megatylopus cf. M. matthewi Webb. ?Agriotherium schneideri is represented by a pisiform and a single incisor and, therefore, is tentatively identified. The specimens of N. cf. N. catocopis are problematic and call into question some of the diagnostic characters of the large cats of the Hemphillian. The Rhinoceros Hill West site is thought to be Late Hemphillian due primarily to the presence of Nannippus lenticularis, ?Agriotherium schneideri, and Alforjas taylori. Rhinoceros Hill West appears to be equal in age to Rhinoceros Hill, Lost and Found quarries, Edson Quarry, and the Coffee Ranch l.f. (Type Hemphillian) due to the coexistence of a high percentage of species. The taxa of Rhinoceros Hill West are consistent with the grassland or \steppe\ environment of North America during the Late Hemphillian. The fauna is dominated by hypsodont herbivores such as horses and antilocaprids, and open grassland predators such as a variety of cats, a slender-legged bear, and scavenging dogs.