Lenothrix Miller 1903

Lenothrix Miller 1903, Proc. U. S. Natl. Mus ., 26 (1317): 466.

Type Species: Lenothrix canus Miller 1903

Species and subspecies: 1 species:

Species Lenothrix canus Miller 1903

Discussion: Pithecheir Division. Chromosomal and biochemical data suggested a close phylogenetic link between Lenothrix and Niviventer (Chan et al., 1979), and a high divergence from species of Maxomys, which were once placed in Lenothrix (Gadi and Sharma, 1983) . In its cranial and dental morphology, Lenothrix is unlike any species in those genera; derived molar occlusal patterns are much like those in Pithecheir and Lenomys (Chaimanee, 1998; Misonne, 1969; Musser and Newcomb, 1983), but spermatozoal conformation is highly divergent from any Sundaic murine. In sum, Lenothrix is a Sundaic endemic characterized by many primitive external, cranial, dental, and chromosomal features and a few derived dental and spermatozoal traits; despite several claims, its phylogenetic relationships still require illumination (see discussions in Chaimanee, 1998; Breed and Yong, 1986; Musser, 1981 a, b, c; Musser and Newcomb, 1983). Its inclusion here in a Pithecheir Division reflects an hypothesis that has to be tested by analyses of molecular and a range of morphological data. Lenothrix was included in a Pithecheir Section of a larger Micromys Group by Pavlinov et al. (1995 a). Lenothrix may be a member of one of the earliest groups to have diverged from the core murine lineage as represented by a Progonomys like ancestor (Chaimanee, 1998). Sundaic Pithecheir and Pithecheirops, along with Sulawesian Eropeplus, Lenomys, and Margaretamys, are likely members of the same cluster.