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A cloven hoof or split hoof is a hoof split into two toes. This is found on members of the mammalian order Artiodactyla. Examples of mammals that possess this type of hoof are cattle, deer, goats, and sheep. In folklore and popular culture, a cloven hoof has long been associated with the Devil. The two digits of cloven hoofed animals are homologous to the third and fourth fingers of the hand. They are called claws and are named for their relative location on the foot: the outer, or lateral, claw and the inner, or medial claw. The space between the two claws is called the interdigital cleft; the area of skin is called the interdigital skin. The hard outer covering of the hoof is called the hoof wall, or horn. It is a hard surface, similar to the human fingernail. The almost finger-like dexterity available to cloven hoofed mammals like the Mountain Goat and wild sheep combined with a hard outer shell and soft and flexible inner pads provide excellent traction in their precarious habitats. ==Evolution== It is speculated that during the Eocene period, hoofed marsh dwellers carried their body weight mainly on two of the middle toes, which grew to equal size, becoming the Artiodactyla or even-toed hoofed animals. Prior to the close of the Eocene period the side toes of some had dwindled and practically disappeared while the basal pieces or metapodium of the pair of supporting toes became fused together, thus producing the appearance of a cloven hoof. The mammal with a cloven hoof is an even-toed ungulate of order Artiodactyla as opposed to the odd-toed ungulates of Perissidactyla, like the horse, which have one toe, or the rhinoceros, which has three toes. The five-toed ancestors of the earliest Eocene had already developed feet that suggest odd-toed and even-toed descendants to the modern viewer. Even Phenacodus, the most generalized of the early mammals, has a foot in which the central toe is somewhat larger than the others and could be placed in the division of odd toed ungulates, Perissidactyla. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「cloven hoof」の詳細全文を読む スポンサード リンク
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