Carnivora kɑrˈnɪvərə is an order of placental mammals that have specialized in primarily eating flesh, whose members are formally referred to as carnivorans. The order Carnivora is the fifth largest order of mammals, comprising at least 279 species.
Carnivorans live on every major landmass and in a variety of habitats, ranging from the cold polar regions to the hyper-arid region of the Sahara Desert to the open seas. They come in a very large array of different body plans with a wide diversity of shapes and sizes.
Carnivora can be divided into two suborders: the Feliformia, containing the true felines and several feline-like forms, and the Caniformia, containing the true canids (such as wolves and dingos) and many somewhat "dog-like" forms such as sea lions and bears. The feliforms include families such as the cats, the hyenas, the mongooses and the civets. The majority of feliform species are found in the Old World, though the cats and one extinct genus of hyena have successfully diversified into the Americas.
The caniforms include the dogs, bears, raccoons, weasels, and seals. Members of this group are found worldwide and with immense diversity in their diet, behavior, and morphology.
The word carnivore is derived from Latin carō (stem carn-) 'flesh' and vorāre 'to devour', and refers to any meat-eating organism.
The oldest known carnivoran line mammals (Carnivoramorpha) appeared in North America 6 million years after the Cretaceous–Paleogene extinction event. These early ancestors of carnivorans would have resembled small weasel or genet-like mammals, occupying a nocturnal shift on the forest floor or in the trees, as other groups of mammals like the mesonychians and later the creodonts were occupying the megafaunal faunivorous niche. However, following the extinction of mesonychians and the oxyaenid creodonts at the end of the Eocene, carnivorans quickly moved into this niche, with forms like the nimravids being the dominant large-bodied ambush predators during the Oligocene alongside the hyaenodont creodonts (which similarly produced larger, more open-country forms at the start of the Oligocene).