Thamnomys Thomas 1907

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

Type Species: Thamnomys venustus Thomas 1907

Species and subspecies: 3 species:

Species Thamnomys kempi Dollman 1911

Species Thamnomys major Hatt 1934

Species Thamnomys venustus Thomas 1907

Discussion: Oenomys Division. Many have asserted that species of Thamnomys and Grammomys are in the same monophyletic group and separable only at the subgeneric level (G. M. Allen, 1939; Hatt, 1940 a; Hollister, 1919; Misonne, 1974; F. Petter and Tranier, 1975; and others, see references in Meester et al., 1986). Thamnomys is a distinct genus, however, 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 also included rutilans, which is now regarded to be a synonym of Grammomys poensis (see that account). The considerable geographic and individual variation in body size, pelage coloration, and craniodental dimensions in Thamnomys needs to be assessed in a careful systematic revision of the genus. Until then we recognize the three species listed below based upon our examination of specimens and preliminary principle components analysis of cranial and dental measurements.

Oenomys is the closest phylogenetic relative, a view presented more than fifty years ago by Hatt (1940 a:522): " Oenomys and Thamnomys bear much resemblance to each other, and I am inclined to believe that they represent respectively semi-arboreal and arboreal descendants of a common stock." Hatt’s insight has recently been supported by a phylogenetic study incorporating 17 cranial and 23 dental traits (Lopez-Martinez et al., 1998).