Castor

Castor is a genus of beavers, family Castoridae, in the rodent suborder Castorimorpha, comprising two living species, the North American beaver and the Eurasian beaver. Beavers are large semiaquatic rodents, the second-largest living rodents after capybaras, weighing up to 50 kilograms and distinguished by long chisel-like incisors, webbed back feet and flat, scaly tails; the two species differ in skull shape, tail form and fur color. The North American species ranges through most of the United States and Canada and northern Mexico, with introduced populations in Finland, Russia and Patagonia, while the Eurasian species occurs across western, central and eastern Europe and western Russia and the Scandinavian Peninsula, with small populations in Mongolia and northwestern China.