Perissodactyls have a diverse fossil record although there are only 6 modern genera of horses, tapirs, and rhinos.  Perissodactyls are easily recognized by their odd number of toes, unlike the artiodactyls which possess an even number of toes.  The primitive arctocyonids evolved into the condylarth family Phenacodontidae that included Early Eocene forms like Loxolophus which had a short diastema behind the first premolar and Karagalax, a tapiroid.  In Phenacodus, digits I and V are reduced on both hands and feet.  Tetraclaenodon was closer to horse ancestry.  Homogalax was the ancestor of tapirs, including basal species of tapir such as Heptodon,  Helates (Eocene), and Prototapir (Oligocene) (Maas, 2001).  

     Tapirs possess five digits on their front legs (although the thumb is vestigial) and three digits on their hind legs.  They are nocturnal animals which inhabit areas near water.  Jaguars and humans are their primary predators.  They are herbivores. 

The skull of a modern tapir is depicted below.

skull skull