Class Mammalia Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Suborder Sciurognathi (Tullberg, 1899) see Suborder Sciuromorpha Brandt, 1855
       Family Muridae Batsch, 1788 - rats, mice, hamsters, voles, lemmings, and gerbils
         Subfamily Arvicolinae Gray, 1821 - voles
           Genus Arvicola Lacépède, 1799 - water voles
             1 Arvicola sapidus Miller, 1908 - southwestern water vole
             2 Arvicola terrestris (C. Linnaeus, 1758) - European water vole