eohippus

English Thesaurus

1. earliest horse; extinct primitive dog-sized four-toed Eocene animal (noun.animal)

hypernym	:	equus caballus, horse,
definition	:	solid-hoofed herbivorous quadruped domesticated since prehistoric times (noun.animal)

member meronym	:	genus hyracotherium, hyracotherium,
definition	:	extinct horse genus; formerly called eohippus (noun.animal)