The even-toed ungulates form the mammal order Artiodactyla (artios even + daktulos toe), the group that contains the pigs, peccaries, hippopotamuses, camels, chevrotains (mouse deer), deer, giraffes, pronghorn, antelopes, sheep, goats, and cattle. They are ungulates whose weight is borne about equally by the third and fourth toes, rather than mostly or entirely by the third as in odd-toed ungulates (perissodactyls). Another key distinguishing feature is the shape of the astragalus, a bone in th… (More on Artiodactyla)