Deomys Thomas 1888

Deomys Thomas 1888, Proc. Zool. Soc. Lond., 1888: 130.

Type Species: Deomys ferrugineus Thomas 1888

Species and subspecies: 1 species:

Species Deomys ferrugineus Thomas 1888

Discussion: Described by Thomas (1888 c:132) as a unique member of a "special section" within Muridae (Deomyes) with molar traits intermediate between cricetines and murines. A year later, Lydekker (1889) referred Deomys to the Deomyinae; subsequently, Thomas (1896) placed Deomys in the Dendromurinae, and with the exception of Ellerman, (1941), there it remained until the 1990 s (see historical discussions in Rosevear, 1969, and Carleton and Musser, 1984). The morphological traits of Deomys do not fit well in the Dendromurinae (Carleton and Musser, 1984; Rosevear, 1969), which influenced Ellerman (1941) to propose Deomyinae (primarily because of its peculiar and morphologically primitive conformation of the zygomatic plate) to contain the genus (Ellerman listed Thomas’s Deomyes as a synonym and was apparently unaware of Lydekker’s Deomyinae). Recent DNA-DNA hybridization experiments (Denys et al., 1995) and phylogenetic analyses of mtDNA cytochrome b sequences (E. Verheyen et al., 1995), nuclear protein-coding DNA sequences (LCAT, Michaux and Catzeflis, 2000; LCAT and vWF, Michaux et al., 2001), and the combination of DNA/DNA hybridization and mitochondrial and nuclear DNA sequences (Chevret et al., 2001) consistently placed Deomys in the same clade as Acomys, Lophuromys, and Uranomys . Phylogenetic analyses of dental traits, however, did not group Deomys with the acomyines (Denys et al., 1995). Sperm morphology of Deomys is highly derived compared with species of Dendromurinae and indicates it does not belong with that subfamily (Breed, 1995 d), but Breed did not include it within the Acomys-Uranomys group he defined using spermatozoal characters. Deomys ferrugineus feeds mostly on insects, millipedes, centipedes, slugs and crustacea (Genest-Villard, 1980) and its unique zygomasseteric morphology and molar topography may reflect adaptations to that diet. In reporting their results based on mtDNA sequences, E. Verheyen et al. (1996 b:784) suggested that "the clustering of Deomys with the Lophuromys clade may be less surprising than has been suggested elsewhere (Denys et al., 1995). The Deomys skull is not only very distinct from that of other dendromurines, but its zygomatic plate and internal organs (stomach) have been reported to resemble the same features in Lophuromys ." Even Ellerman (1941:317) admitted that the zygomatic plate of Deomys resembled that of Lophuromys . Osgood (1936:238) described how the pelage of Deomys has a "more superficial resemblance to Acomys than to any other well-known genus," pointed to configuration of auditory bulla and petrosal as being similar in Deomys and Lophuromys, and noted that Tullberg (1899) commented on the similarity in anterior portion of skull and internal organs with Lophuromys .