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 Microsciurus Allen, 1895 - American pygmy squirrels Microsciurus alfari (J.A. Allen, 1895) - Alfaro's pygmy squirrel