Oreodont

Oreodonts were horse-like mammals that lived during the miocene to the pliocene epoch. Oreodonts were very small only about 1 metre long, oreodonts closest living relatives are chevrotains aka mouse deer. Oreodonts main predators were Archaeotherium or terminator pigs. Oreodonts mainly lived in small groups.

In the series...
A herd of defenseless oreodonts were seen grazing before being ambushed by an terminator pig.