Thallomys Thomas, 1920 . Ann. Mag. Nat. Hist., ser. 9, 5:141.

TYPE SPECIES: Mus nigricauda Thomas, 1882 .

COMMENTS: After being proposed as a genus by Thomas (1920), Thallomys was used in checklists (e.g., Allen, 1939; Ellerman, 1941) until Ellerman et al. (1953) united it with subgenus Aethomys of Rattus . Thallomys was reinstated by Lundholm (1955c), who also suggested it was closely related to Thamnomys . Misonne (1969) pointed out that Thallomys has nothing to do with Rattus, and is most closely related to Tertiary european Parapodemus, an evaluation based on molar occlusal patterns. Although clearly unrelated to Rattus, Thallomy's phylogenetic position within the diversity of African murines is still unresolved.

Early checklists and faunal accounts recognized several species (Ellerman, 1941; Roberts, 1951), but for last 20-30 years, Thallomys has been either treated as monotypic (D. H. S. Davis, 1965; Meester et al., 1986; Misonne, 1974), or as containing at least two species (Petter, 1973a; Skinner and Smithers, 1990). That considerable and significant morphological diversity exists in the genus has been acknowedged. D. H. S. Davis (1965), for example, recognized five groups of subspecies. Petter (1973a) clearly demonstrated that at least two species could be diagnosed. Regional faunal reports of southern African mammals discussed presence of two distinct kinds (Skinner and Smithers, 1990; Smithers and Wilson, 1979). Meester et al. (1986) announced the need for revision of Thallomys, and that both morphological and chromosomal data suggested the presence of two species (see Gordon, 1987). We list four species. Our review is based on original descriptions of taxa, Roberts' (1951) useful monograph and other regional faunal reports, large collections of specimens, and holotypes. Gastric anatomy reported by Perrin (1986).