Comments: | Although initially classified within Murinae (e.g., Ellerman, 1941; Simpson, 1945; Thomas, 1896), systematists have acknowledged a closer affinity of African pouched rats to one another than to other murines, a distinction later formalized by Roberts’ (1951) diagnosis of Cricetomyinae. Most subsequent systematic arrangements have followed F. Petter (1966a) in allying cricetomyines with cricetids (Reig, 1980, 1981; Rosevear, 1969) based on his interpretation of molar cusp homologies. Lavocat (1973, 1978) first suggested phylogenetic association with other archaic African groups in a broadly defined Nesomyidae, an interpretation generally endorsed by Carleton and Musser (1984). Configuration of molar cusps (F. Petter, 1966a), anatomy of internal cheek pouches (Ryan, 1989b), and mitochondrial and nuclear DNA sequence data (Jansa et al., 1999; Michaux et al., 2001b; Michaux and Catzeflis, 2000) support the monophyly of the subfamily, which forms an unresolved polytomy with species of Dendromurinae and Mystromys according to phyletic evaluation of nuclear protein-coding genes (Michaux et al., 2001b; Michaux and Catzeflis, 2000). General and diagnostic morphological traits, taxonomic history, and phylogenetic interpretations summarized by Carleton and Musser (1984). Certain early to middle Miocene taxa of East Africa (e.g., Leakeymys and Notocricetodon) have been speculatively linked to the autochthonous African origin of Cricetomyinae, but their phyletic association so far lacks persuasive demonstration (see Chaline et al., 1977; Tong and Jaeger, 1993). Indisputable fossil representatives extend from the early Pliocene to the Recent of eastern and southern Africa (McKenna and Bell, 1997). Roberts (1951) taxonomically segregated Saccostomus (Saccostomurinae) from other African pouched rats (Cricetomyinae), a division not recognized by later systematists (F. Petter, 1966a; Ryan, 1989b). Many morphological traits, however, depict Beamys and Cricetomys as sister species apart from Saccostomus, as enumerated by Carleton and Musser (1984), and we employ those family-group taxa as tribes. The closer affinity of Beamys and Cricetomys is also reflected in gene-sequence analyses (Corti et al., 2004). |