Class Mammalia Linnaeus, 1758 - mammals
Order Rodentia Bowdich, 1821 - rodents
Suborder Sciurognathi (Tullberg, 1899)
see Suborder Sciuromorpha Brandt, 1855
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 concinnus Thomas, 1888 - Philippine pygmy squirrel