Giraffidae

Giraffidae (giraffe, okapi; infra-order Pecora, superfamily Cervoidea) An artiodactyl family, now represented by only the giraffe and okapi of Africa, which diverged from the Cervidae during the Miocene. Relatively short-necked and short-legged forms like the okapi are known as fossils from the Pliocene of Eurasia, and in the Pleistocene of Africa and southern Eurasia there were very large, heavily built giraffids with branched horns, the best-known example being Sivatherium. The okapi is almost indistinguishable from the Pliocene genus Palaeotragus. Both sexes bear short horns covered by skin, but extinct forms grew larger horns (e.g. Samotherium and Sivatherium). Giraffidae are long-legged, and in the giraffe (Giraffa camelopardalis) the weight of the body is balanced on the fore limbs, the number of ribs is reduced, and the hind part of the spinal column functions as part of the hind limbs, which provide propulsion. The gait is ‘rocking’, both limbs of one side of the body moving together. There are mechanisms that regulate blood flow when the head is raised. There are two genera (Giraffa and Okapia), found in Africa south of the Sahara.