Ungulates are hoofed mammals. Hooves are enlarged claws on the toes. Ungulates are digitigrade; they walk on their toes. The word ungulate is from the Latin word unguis, which means nail, claw, or hoof. Many hoofed mammals live in grasslands and savannahs. Ungulates have evolved features that are adaptive for life on open grasslands, in particular long legs to increase running speed. They can walk on their toes.

Artiodactyls are even-toed (cloven-hooved) ungulates - some of these include antelopes, camels, cows, deer, goats, pigs, and sheep. These animals walk on two enlarged toes.

Perissodactyls are odd-toed ungulates (a much smaller group) - some of these include horses, zebras, rhinoceroses, and tapirs. Rhinoceroses and tapirs walk on three enlarged toes. Living horses and zebras walk on one enlarged toe.

The odd- and even-toed ungulates are still referred to as the "true ungulates", but fossil and molecular evidence have resulted in the expansion of the term "ungulate". Currently included in the group are the elephants, sea cows, hyraxes, and aardvarks. Recent discoveries suggest the addition of the Cetaceans (whales and dolphins).