OenomysDivision. A distinctive genus as asserted by Ellerman (1941) and other workers (e.g., Hutterer and Dieterlen, 1984; Misonne, 1969; Rosevear, 1969), and not part of Thamnomys with which it has often been united as a subgenus (G. M. Allen, 1939; Hatt, 1940b; Hollister, 1919; Misonne, 1974; F. Petter and Tranier, 1975). Morphological and chromosomal similarities exist with Thallomys (Olert et al., 1978). Analysis of microcomplement fixation of albumin associated Grammomys with Lemniscomys, Pelomys, Rhabdomys, and Thallomys (Watts and Baverstock, 1995a). Research using mitochondrial gene sequences (DNA cytochrome b, 12S and 16S rRNA fragments) placed Grammomys next to Aethomys within an African murine clade consisting of Hybomys, Dasymys, Lemniscomys, Rhabdomys, Desmomys, Pelomys, Mylomys, and Arvicanthis (Ducroz et al., 2001). Partly reviewed by F. Petter and Tranier (1975) and Hutterer and Dieterlen (1984), who provided morphological, distributional, and chromosomal comparisons.

Two of the species listed below, G. kuru and G. poensis (both formerly included in G. rutilans; see Musser and Carleton, 1993, for example), along with an undescribed species from Mt Oku in W Cameroon, form a monophyletic group separate from the other species of Grammomys and will eventually be placed in a new genus (R. Hutterer, pers. comm., 2002). The taxa kuru and poensis (and rutilans, which is unavailable) have been considered members of Thamnomys (G. M. Allen, 1939; Ellerman, 1941; Hutterer and Dieterlen, 1984), but external, cranial, and dental morphology is more similar to that characterizing species of Grammomys (where it was listed by D. H. S. Davis, 1965, and Misonne, 1974), and we include them within that genus pending publication of Hutterer’s revision (he also provided most of the information for the two accounts). Fossils identified as Grammomys come from Pliocene-Pleistocene strata of East Africa and South Africa (Avery, 2000; Jaeger, 1976; Jaeger and Wesselman, 1976; see review by Denys, 1999) and Pleistocene sediments of Namibia (Senut et al., 1992).