Lophuromys (Lophuromys) chrysopus Osgood 1936

Lophuromys (Lophuromys) chrysopus Osgood 1936, Zool. Ser. Field Mus . Nat. Hist., 20: 242.

Type Locality: Ethiopia, Sidamo Province, Allata.

Vernacular Names: Ethiopian Forest Brush-furred Rat.

Distribution: Endemic to Ethiopia in montane forests of the E and W plateaus (separated by the Ethiopian Rift Valley); probably occurs in most forests of the SW mountains (Lavrenchenko et al., 1998 b).

Discussion: Subgenus Lophuromys, L. aquilus species group (W. Verheyen et al., 2002). Described as a subspecies of L. aquilus by Osgood (1936) but subsequently included in L. flavopunctatus (Yalden et al., 1976, 1996). Allozymic, chromosomal, as well as morphological and morphometric data (Aniskin et al., 1997; Lavrenchenko et al., 1998 b, 2000; W. Verheyen et al., 2002) distinguish chrysopus as a separate species from both L. flavopunctatus and L. brevicaudus . The chromosomal composition alone signaled the distinctness of chrysopus (2n = 54, FN = 60, as contrasted with 2n = 68, FN = 78 for brevicaudus; and 2n = 68 for flavopunctatus; Aniskin et al., 1997). Differences between samples from E and W plateaus in morphometrics, pelage coloration, and distribution of B-chromosomes suggest some geographic differentiation in L. chrysopus (Lavrenchenko et al., 1998 b) . Morphometric analyses place L. chrysopus in the same cluster as the Ethiopian L. brunneus and montane Kenyan L. zena, and separate from the group formed by geographic samples of L. aquilus (W. Verheyen et al., 2002) . Those authors also noted that holotypes of Cameroon eisentrauti and dieterleni, Mt Elgon rubecula, and Kenyan zena cluster with samples of L. chrysopus, suggesting all represent the same species, a possibility requiring testing by analysis of morphometric, chromosomal, and molecular variation in highland samples from the region between Ethiopia and the Cameroon and Kenyan mountains. In the Harenna forest block on S slopes of Bale Mtns, L. chrysopus is one of the most abundant rodents in tropical evergreen rainforest between 1550 and 2760 m and is sympatric with the heathland L. brevicauda from 2400 to 2760 m (Lavrenchenko, 2000; Lavrenchenko et al., 1998 b).