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 Sciurillus Thomas, 1914 - Neotropical pygmy squirrel Sciurillus pusillus E. Geoffroy, 1803 - South American pygmy squirrel