Any meat-eating animal, but especially any member of the order Carnivora, consisting of 12 families of primarily predatory mammals: Canidae (e.g., dogs), Ursidae (bears), Procyonidae (raccoons), Mustelidae (weasels), Mephitidae (skunks), Viverridae (civets), Herpestidae (mongooses), Hyaenidae (hyenas), Felidae (cats), Otariidae and Phocidae (seals), and Odobenidae (the walrus). Though most carnivores eat only meat, some rely heavily on vegetation (e.g., the panda). Most have a complex tooth structure and a lower jaw that can move only vertically but can exert great power. The earliest carnivores, which probably evolved from an insectivorous ancestor, appeared during the Paleocene Epoch (about 65–55 million years ago). Carnivores are highly intelligent.