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 Lutrinae Bonaparte, 1838 - otters
             1 Genus Aonyx Lesson, 1827 - clawless otters
             2 Genus Enhydra Fleming, 1822 [monotypic] - sea otter
             3 Genus Hydrictis Pocock, 1921 [monotypic]
             4 Genus Lontra Gray, 1843
             5 Genus Lutra Brisson, 1762 - river otters
             6 Genus Lutrogale Gray, 1865 [monotypic]
             7 Genus Pteronura Gray, 1837 [monotypic] - giant otter