Hoofed mammals are either even-toed or odd-toed.
The hoof developed for animals who were in need of quickly escaping from predators. Whereas hooves, like claws and nails, touch the ground, the foot does not, so it becomes part of the leg, increasing the animal's stride length and thus its running speed. Hooves have a structure similar to that of a nail. Hooved mammals are called ungulates.
Even-Toed Ungulates
Even-toed ungulates are animals whose weight is borne equally on two toes, called cloven hoofs. Some have only two toes, while others have two additional much smaller toes. About 220 species of animals comprise this group, including antelope, cattle, llamas, camels, deer, giraffes, okapis, hippopotamuses, peccaries, chevrotains, pronghorn, sheep, goats, hogs and pigs. This group also includes the now extinct entelodonts.
Odd-Toed Ungulates
Odd-toed ungulates have one or three toes, with the middle toe on three-toed mammals usually being larger. Consisting of only 17 species, they are a much smaller group than the even-toed ungulates. The three families that make up this category are rhinoceroses, tapirs and horses, but also prehistorically includes the paraceratherium and propalaetherium. As grazing animals, odd-toed ungulates have an enlarged segment in their large intestine that contains bacteria to assist in digestion.
Dewclaws
Some even-toed ungulates may also have dewclaws on the outer part of each foot, further up the leg than the main hoof. The dewclaws of some mammals never reach the ground, such as in cattle. In species including pigs and many types of deer, the dewclaws are smaller, and so touch the ground when the animal jumps or is on soft ground.
Tapir
The tapir is a uniquely hoofed animal, as it has four toes on the front foot and three toes on the back foot. Although it looks like a pig, it is related to the horse, zebra and rhinoceros. Tapirs can be one of four species. The Malayan tapir has a white front, black back legs and silvery white rear. The Brazilian tapir, mountain tapir and Baird's tapir all have a dark brown or red back and pale underside.
Tags: much smaller, three toes, touch ground, ungulates have