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 Sigmodontinae Wagner, 1843
           Genus Phaenomys Thomas, 1917 - Rio de Janeiro rice rat
             1 Phaenomys ferrugineus Thomas, 1894 - Rio de Janeiro rice rat