Class [Mammalia] Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Family Sciuridae Batsch, 1788 - squirrels, chipmunks, marmots, and prairie dogs
       Subfamily Sciurinae Batsch, 1788 - tree and ground squirrels
         Genus Spermophilus Cuvier, 1825 - ground squirrels
           01 Spermophilus adocetus Merriam, 1903 - tropical ground squirrel
           02 Spermophilus alaschanicus - Alashan ground squirrel see Spermophilus alashanicus Büchner, 1888
           03 Spermophilus annulatus Audubon & Bachman, 1842 - ring-tailed ground squirrel
           04 Spermophilus armatus Kennicott, 1863 - Uinta ground squirrel
           05 Spermophilus atricapillus W. Bryant, 1889 - Baja California rock squirrel
           06 Spermophilus beecheyi (Richardson, 1829) - California ground squirrel
           07 Spermophilus beldingi Merriam, 1888 - Belding's ground squirrel
           08 Spermophilus brunneus (A.H. Howell, 1928) - Idaho ground squirrel
           09 Spermophilus citellus Linnaeus, 1766 - European souslik
           10 Spermophilus columbianus (Ord, 1815) - Columbian ground squirrel
           11 Spermophilus dauricus Brandt, 1843 - Daurian ground squirrel
           12 Spermophilus elegans Kennicott, 1863 - Wyoming ground squirrel
           13 Spermophilus erythrogenys Brandt, 1841
           14 Spermophilus franklinii (Sabine, 1822) - Franklin's ground squirrel
           15 Spermophilus fulvus Lichtenstein, 1823 - large-toothed souslik
           16 Spermophilus lateralis (Say, 1823) - golden-mantled ground squirrel
           17 Spermophilus madrensis Merriam, 1901 - Sierra Madre ground squirrel
           18 Spermophilus major Pallas, 1778 - russet souslik
           19 Spermophilus mexicanus (Erxleben, 1777) - Mexican ground squirrel
           20 Spermophilus mohavensis Merriam, 1889 - Mohave ground squirrel
           21 Spermophilus musicus Ménétries, 1832
           22 Spermophilus parryii (Richardson, 1825) - Arctic souslik
           23 Spermophilus perotensis Merriam, 1893 - Perote ground squirrel
           24 Spermophilus pygmaeus Pallas, 1778 - little souslik
           25 Spermophilus relictus Kashkarov, 1923 - Tien Shan souslik
           26 Spermophilus richardsoni - Richardson's ground squirrel see Spermophilus richardsonii (Sabine, 1822)
           27 Spermophilus saturatus (Rhoads, 1895) - Cascade golden-mantled ground squirrel
           28 Spermophilus spilosoma Bennett, 1833 - spotted ground squirrel
           29 Spermophilus suslicus Güldenstaedt, 1770 - spotted souslik
           30 Spermophilus tereticaudus Baird, 1858 - round-tailed ground squirrel
           31 Spermophilus townsendii Bachman, 1839 - Townsend's ground squirrel
           32 Spermophilus tridecemlineatus (Mitchill, 1821) - thirteen-lined ground squirrel
           33 Spermophilus undulatus Pallas, 1778 - long-tailed souslik
           34 Spermophilus variegatus (Erxleben, 1777) - rock squirrel
           35 Spermophilus washingtoni (A.H. Howell, 1938) - Washington ground squirrel
           36 Spermophilus xanthoprymnus Bennett, 1835