An extinct mammal of the horse family, but not larger than a sheep, and having three toes on each foot.
A genus of prehistoric horse that lived in what is now North America during the Oligocene Period some 25 to 40 million years ago and having three usable hoofs on each foot.
Referring to the Rocky Mountain region: A genus of American Eocene mammals allied to the horse, but having four toes in front and three behind.
A genus of fossil horses from the Lower Pliocene.
They had three toes on each foot, the lateral ones being small.