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 Pteromyinae Brandt, 1855 - flying squirrels
                           Genus Hylopetes Thomas, 1908 - pygmy flying squirrels
                             Hylopetes lepidus (Horsfield, 1824) - grey-cheeked flying squirrel