Thamnomys Thomas, 1907 . Ann. Mag. Nat. Hist., ser. 7,19: 121.

TYPE SPECIES: Thamnomys venustus Thomas, 1907 .

COMMENTS: Despite assertions that species of Thamnomys and Grammomys are in the same monophyletic group but separable at the subgeneric level (Allen, 1939; Hatt, 1940a; Hollister, 1919; Misonne, 1974; Petter and Tranier, 1975; and others—see references in Meester et al., 1986), Thamnomys is a distinct genus, as explained by Ellerman (1941), Hutterer and Dieterlen (1984), Misonne (1969), Rosevear (1969), and other workers (see references in Meester et al., 1986). Those systematists, however, also included rutilans in Thamnomys, but we place it in Grammomys pending systematic revision of rutilons .

Oenomys is the closest phylogenetic relative, a view presented more than fifty years ago by Hatt (1940a:522): "Oenomys and Thamnomys bear much resemblance to each other, and I am inclined to believe that they represent respectively semiarboreal and arboreal descendants of a common stock."