One species, Canis familiaris, apparently was introduced into Australia by human agency in prehistoric time and subsequently established wild populations on that continent. The Pinnipedia are here treated as a full order, the account of which should be seen for further information on questions regarding its classification. The largest is the grizzly or brown bear, some individuals of which, particularly along the coast of southern Alaska, attain a head and body length of 2,800 mm and a weight of 780 kg.
Carnivores have four or five clawed digits on each limb.
Some carnivores, including canids and felids, are digitigrade, walking only on their toes. Others, such as ursids, are plantigrade, walking on their soles with the heels touching the ground. The brain has well-developed cerebral hemispheres, and the skull is heavy, with strong facial musculature. The stomach is simple. Males have a baculum.