The Sea Mink, Neovison macrodon, is an extinct North American member of the family Mustelidae

Mustelidae

Mustelidae , commonly referred to as the weasel family, are a family of carnivorous mammals. Mustelids are diverse and the largest family in the order Carnivora, at least partly because in the past it has been a catch-all category for many early or poorly differentiated taxa...

. It is the only mustelid, and one of only two terrestrial mammal species in the order Carnivora

Carnivora

The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...

, to become extinct in historic times (along with the Falkland Islands Wolf). The body of the sea mink was significantly longer than that of the closely related American Mink

American Mink

The American mink is a semi-aquatic species of Mustelid native to North America, though human intervention has expanded its range to many parts of Europe and South America. Because of this, it is classed as Least Concern by the IUCN. Since the extinction of the sea mink, the American mink is the...

 (N. vison), and also bulkier, leading to a pelt that was almost twice the size of the other species.