The Collaborative International Dictionary of English v.0.48:

Coryphodon \Co*ryph"o*don\ (k?-r?f"?-d?n), n. [Gr. koryfh` head,
   peak + 'odoy`s, 'odo`ntos, tooth.] (Paleon.)
   A genus of extinct mammals from the eocene tertiary of Europe
   and America. Its species varied in size between the tapir and
   rhinoceros, and were allied to those animals, but had short,
   plantigrade, five-toed feet, like the elephant.
   [1913 Webster]