Kingdom [Animalia] Linnaeus, 1758 - animals
   Subkingdom Metazoa Haeckel, 1874 see Kingdom Animalia Linnaeus, 1758
     Division Eumetazoa Butschli, 1910 see Subkingdom Eumetazoa Butschli, 1910
       Subdivision Bilateralia
         Phylum Chordata Bateson, 1885 - chordates
           Subphylum Vertebrata Cuvier, 1812 - vertebrates
             Class Mammalia Linnaeus, 1758 - mammals
               Subclass Eutheria Gill, 1872 see Infraclass Eutheria Gill, 1872
                 Order Rodentia Bowdich, 1821 - rodents
                   Suborder Sciuromorpha Brandt, 1855
                     Superfamily Sciuroidea Batsch, 1788
                       Family Sciuridae Batsch, 1788 - squirrels, chipmunks, marmots, and prairie dogs
                         Subfamily Sciurinae Batsch, 1788 - tree and ground squirrels
                           Tribe Sciurini Batsch, 1788
                             Genus Sciurus Linnaeus, 1758 - tree squirrels
                               Subgenus Guerlinguetus
                               Sciurus aberti Woodhouse, 1853 - tassel-eared squirrel
                               Sciurus anomalus Schreber, 1785 - Persian squirrel
                               Sciurus apache J.A. Allen, 1893 see Sciurus nayaritensis J.A. Allen, 1890
                               Sciurus arizonensis Coues, 1867 - Arizona grey squirrel
                               Sciurus carolinensis Gmelin, 1788 - eastern grey squirrel
                               Sciurus griseus Ord, 1818 - western grey squirrel
                               Sciurus kaibabensis Merriam, 1904 see Sciurus aberti Woodhouse, 1853
                               Sciurus niger Linnaeus, 1758 - eastern fox squirrel
                               Sciurus vulgaris Linnaeus, 1758 - Eurasian red squirrel