Hoof

The hoof (pl.: hooves) is the tip of a toe of an ungulate mammal, which is covered and strengthened with a thick and horny keratin covering.^[1] Artiodactyls 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, goat, and sheep.^[2] The feet of perissodactyl mammals have an odd number of toes, e.g. the horse, the rhinoceros, and the tapir.^[3] Although hooves are limb structures primarily found in placental mammals, hadrosaurs such as Edmontosaurus possessed hoofed forelimbs. The marsupial Chaeropus also had hooves.^[4]