A large, semi-aquatic, south american rodent, also known as nutria, introduced into Britain for fur farming around 1929. Escaped animals established feral populations which were eradicated by 1989. Widely introduced into North America, Europe, N Asia, and E Africa.
Coypu skulls have a wide infraorbital foramen, a deep jugal bone and a long paraoccipital process. The retained deciduous premolar is an important taxonomic feature at the family level.