; suborder Fissipedia (or Caniformia), superfamily Canoidea)
A family of carnivores that are characteristic mainly of northern temperate latitudes, where they occupy niches similar to those occupied by the Viverridae of lower latitudes. They are relatively primitive, with short, stocky legs. They have long, sharp canine teeth and well-developed carnassials but, in modern forms, never more than one post-carnassial molar in each jaw. Most are small, but a Miocene American mustelid, Megalictis, was the size of a black bear. They had diverged from their miacid ancestors by the Eocene–Oligocene transition and later branched widely, one line giving rise to the seals (Phocidae). The largest modern mustelid is Gulo gulo (wolverine, glutton, carcajou, or skunk bear) of Arctic regions, which grows to more than 1 m in length and a weight of more than 18 kg. Some (e.g. Meles and Taxidea, the Old and New World badgers) have adapted to an omnivorous diet, as has Mellivora capensis (honey badger or ratel) of Asia. The family also includes the martens (e.g. Martes martes, pine marten of Eurasia), and Mustela (weasel, stoat (or ermine), and mink). Otters (e.g. Lutra) have adapted to a semi-aquatic way of life and a diet consisting mainly of fish, with Enhydra becoming wholly marine. Mustelids are distributed throughout the world, except for Madagascar and Australasia. Mephitis (skunk), adapted to an omnivorous diet, was formerly classified in the Mustelidae, but on the basis of DNA comparisons this genus is now usually placed in its own family, Mephitidae. Excluding Mephitis, there are 22 living mustelid genera, with 59 species.
Subjects: Zoology and Animal Sciences.