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 Tamiasciurus Trouessart, 1880 - American red squirrels
           1 Tamiasciurus douglasii (Bachman, 1839) - Douglas' squirrel
           2 Tamiasciurus hudsonicus (Erxleben, 1777) - American red squirrel
           3 Tamiasciurus mearnsi Townsend, 1897