Hoof

The hoof (pl.: hooves or hoofs) is the tip of a toe of an ungulate mammal, which is covered and strengthened with a thick and horny keratin covering.

Hooves are present in some even-toed and odd-toed placental mammals, as well as in some nonmammalians.

• Artiodactyls (Ancient Greek: ἄρτιος : ártios "even", and δάκτυλος : dáktulos "toe") are even-toed ungulates, species whose feet have an even number of digits; the ruminants with two digits are the most numerous, e.g. giraffe, deer, bison, cattle, goats, gazelles, antelopes, pigs, and sheep.
• The feet of perissodactyl (Ancient Greek: περισσός : perissós : uneven", and δάκτυλος : dáktulos "toe") mammals have an odd number of toes, e.g. the horse, the rhinoceros, and the tapir.
• Although hooves are limb structures primarily found in placental mammals, hadrosaurs such as Edmontosaurus possessed hoofed hindlimbs. The marsupial Chaeropus also had hooves.