from the GNU version of the Collaborative International Dictionary of English
- n. An extinct genus of horses from the Pliocene deposits. Each foot had a single toe (or hoof), as in the common horse.
from The Century Dictionary and Cyclopedia
- n. A genus of fossil horses or Equidæ from the Pliocene of North America.
- n. [lowercase] A horse of this genus.
Sorry, no etymologies found.