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