Synonyms: Helaletes pumilus; Helohippus pumilus; Helotherium procyoninum; Hyrachyus pumilus; Hyracotherium osbornianum; Hyracotherium procyoninum; Lambdotherium procyoninum; Lophiotherium ballardi; Oligotomus cinctus; Orohippus atavus; Orohippus ballardi; Orohippus cinctus; Orohippus osbornianus; Orohippus procyoninus; Orohippus pumilus; Orohippus typicus; Orotherium ballardi; Pachynolophus ballardi; Pachynolophus cinctus; Pachynolophus pumilus; Pliolophus cinctus