Class Mammalia Linnaeus, 1758 - mammals
   Order Carnivora Bowdich, 1821 - carnivores
     Family Mustelidae Batsch, 1788 - weasels, badgers, skunks, and otters
       Subfamily Lutrinae Bonaparte, 1838 - otters
         Genus Lontra Gray, 1843
           1 Lontra canadensis (Schreber, 1777) - North American river otter
           2 Lontra felina (Molina, 1782) - marine otter
           3 Lontra longicaudis (Olfers, 1818) - Neotropical otter
           4 Lontra provocax (Thomas, 1908) - southern river otter