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 Exilisciurus Moore, 1958 - pygmy squirrels Exilisciurus exilis Müller, 1838 - plain pygmy squirrel