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Tubulidentata (cohort Ferungulata, superorder Protoungulata) An order comprising the monospecific family Orycteropodidae (Orycteropus afer, the aardvark or ant bear), an isolated form with a skeleton similar to that of Condylarthra, for which reason it is included in the Protoungulata. Fossil forms are known from the Miocene of Africa and the Pliocene of Eurasia, and some Eocene and Oligocene material may also belong to this group. The order derives its name from the teeth, each of which consists of many hexagonal columns of dentine separated by tubes of pulp. There are about 10 teeth in each jaw of the adult, but there is a full complement of milk teeth in juveniles. The teeth lack enamel. Although an ant-eater, the jaw of the aardvark is little reduced, The snout is long, the mouth round, and the tongue long. The back is highly curved. There are four digits on each fore limb and five on the hind limbs, with nails apparently intermediate between claws and hoofs, used for digging. The brain is small and primitive. The aardvark is about the size of a pig, feeds almost exclusively on ants and termites, and is distributed widely throughout Africa south of the Sahara. Supposed tubulidentates from the Pleistocene of Madagascar have recently been placed, by Ross McPhee, in a separate order of mammals, Bibymalagasia.