Myocastor

Myocastor is a genus of rodents, family Echimyidae, functionally monotypic with a single living species, the nutria or coypu, Myocastor coypus, native to South America, along with three extinct fossil species; the genus temporal range extends from the Late Miocene to the present. Its name derives from Ancient Greek for rat-beaver. The nutria was previously classified with Caribbean hutias in family Capromyidae, then placed in its own family Myocastoridae, before molecular studies moved the genus into Echimyidae.