The artiodactyls are the even-toed hoofed mammals and include such
familiar forms as pigs, camels, deer, goats, sheep, and hippopotamuses.
This is a large and varied group of animals, but the basic anatomical
structure of the limbs and teeth show well the relationship between the
different forms. Artiodactyls are abundant fossils in rocks ranging from
Eocene to Pleistocene in age and are common in rocks of this age in
Texas.