UNGULATE

generally, any hoofed mammal. Although the term is no longer used in formal classification, it is still widely applied to a diverse group of placental mammals that are characterized as hoofed, herbivorous quadrupeds. The feature that unites them, the hoof, consists of hornlike dermal (skin) tissue, comparable to the human fingernail, which extends over the end of a broadened terminal digit. Modern hoofed mammals are composed of four orders: Artiodactyla, even-toed ungulates (swine, camels, deer, and bovines); Perissodactyla, odd-toed ungulates (horses, tapirs, and rhinoceroses); Proboscidea (elephants); and Hyracoidea (hyraxes). Ten orders of fossil ungulates are also recognized: Condylarthra (condylarths); Pyrotheria (pyrotheres); Xenungulata (xenungulates); Pantodonta (pantodonts); Dinocerata (uintatheres); Desmostylia (desmostylians); Embrithopoda (embrithopods); Notoungulata (notoungulates, including the toxodonts); Astrapotheria (astrapotheres); and Litopterna (litopterns).