Class [Mammalia] Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Family Muridae Batsch, 1788 - rats, mice, hamsters, voles, lemmings, and gerbils
       Subfamily Hesperomyinae Murray, 1866 - New-World mice and rats see Subfamily Sigmodontinae Wagner, 1843
         Genus Onychomys Baird, 1857 - grasshopper mice
           1 Onychomys arenicola Mearns, 1896 - Mearns' grasshopper mouse
           2 Onychomys leucogaster (Wied-Neuwied, 1841) - northern grasshopper mouse
           3 Onychomys torridus (Coues, 1874) - southern grasshopper mouse