Protohippus

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Protohippus \Pro`to*hip"pus\, n. [NL., from Gr. ? first + ?
     horse.] (Paleon.)
     A genus of fossil horses from the Lower Pliocene. They had
     three toes on each foot, the lateral ones being small.
     [1913 Webster]



From WordNet (r) 2.0 [wn]:

  protohippus
       n : Pliocene horse approaching donkeys in size