Class Mammalia Linnaeus, 1758 - mammals
   Subclass Theria Parker & Haswell, 1897
     Order Carnivora Bowdich, 1821 - carnivores
       Suborder Caniformia Kretzoi, 1943
         Family Mustelidae Batsch, 1788 - weasels, badgers, skunks, and otters
           Subfamily Mustelinae Batsch, 1788 - weasels
             Genus Mustela Linnaeus, 1758 - weasels, ermines, stoats, minks, ferrets, and polecats
               Mustela nivalis Linnaeus, 1766 - least weasel
                 01 [Mustela nivalis nivalis] Linnaeus, 1766
                 02 Mustela nivalis allegheniensis (Rhoads, 1901)
                 03 Mustela nivalis aistoodonnivalis Wu & Kao, 1991
                 04 Mustela nivalis boccamela Bechstein, 1800
                 05 Mustela nivalis campestris Jackson, 1913
                 06 Mustela nivalis caucasica Barrett-Hamilton, 1900
                 07 Mustela nivalis eskimo (Stone, 1900)
                 08 Mustela nivalis heptneri Morozova-Turova, 1953
                 09 Mustela nivalis mosanensis Mori, 1927
                 10 Mustela nivalis namiyei Kuroda, 1921
                 11 Mustela nivalis numidica Pucheran, 1855
                 12 Mustela nivalis pallida Barrett-Hamilton, 1900
                 13 Mustela nivalis pygmaea (Allen, 1903)
                 14 Mustela nivalis rixosa (Bangs, 1896)
                 15 Mustela nivalis rossica Abramov & Baryshnikov, 2000
                 16 Mustela nivalis russelliana Thomas, 1911
                 17 Mustela nivalis stoliczkana Blanford, 1877
                 18 Mustela nivalis tonkinensis Björkegren, 1941
                 19 Mustela nivalis vulgaris Erxleben, 1777