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
Petaurillus hosei Thomas, 1900