caribou, name in North America for the genus ( Rangifer ) of deer from which the Old World reindeer was originally domesticated. Caribou are found in arctic and subarctic regions. They are the only deer in which both sexes have antlers. The broad hooves support the animal (males may weigh over 300 lb/130 kg) on boggy land or snow and have sharp edges that enable it to traverse rocky or frozen surfaces and to dig down to the grass and lichens on which it sometimes feeds. In North America there are several subspecies but two main types: the woodland caribou of the bogs and coniferous forests from Newfoundland to British Columbia, with palmate antlers up to 4 ft (120 cm) wide; and the barren-ground caribou of the tundra of Alaska, N Canada, and Greenland, which has many-branched, slender antlers and which may undertake mass migrations in search of food. Caribou are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Artiodactyla, family Cervidae.