Class [Mammalia] Linnaeus, 1758 - mammals Order Rodentia Bowdich, 1821 - rodents Family Sciuridae Batsch, 1788 - squirrels, chipmunks, marmots, and prairie dogs Subfamily Pteromyinae Brandt, 1855 - flying squirrels Genus Petaurillus Thomas, 1908 - pygmy flying squirrels Petaurillus emiliae Thomas, 1908