Malacomys edwardsi Rochebrune, 1885

Denys, Christiane, Missoup, Alain Didier, Nicolas, Violaine, Sylla, Morlaye, Douno, Mory, Kadjo, Blaise, Lalis, Aude & Monadjem, Ara, 2025, Annotated checklist of rodents from a biodiversity hotspot, Mount Nimba (West Africa), Zoosystema 47 (27), pp. 617-689 : 643

Malacomys edwardsi Rochebrune, 1885

Malacomys edwardsi Rochebrune, 1885: 87 .

REMARKS

We karyotyped two specimens in the field that provided a chromosome formula of 2n=48, NFa=48: MNHN-ZM-2022-944 (SER 164) and MNHN-ZM-2022-945 (SER187), both from Serengbara ( Guinea) ( Appendix 4).

The smaller HF (< 37 mm) and relatively smaller size of our specimens allowed us to attribute them in the field to M. edwardsi , which was later confirmed by molecular analysis. They harbour a soft short and dense pelage of dark brown color dorsally and a light grey belly similar to the holotype of M. edwardsi . The tail is longer than the HB length, bicolored and without hairs. The hands and feet are white, while the large translucent ears are black. The nose is long with long vibrissae (> 5 cm). In size the new specimens from Nimba and Liberia fit well with specimens collected by Lamotte and Coe (1975). They are smaller than M. cansdalei , especially in their hindfeet length ( Table 7 ).

The skull is long ( c. 38 mm) with a prominent long rostrum. The incisive foramina and pterygoid fossae are wide. The anteorbital foramen is very wide and the zygomatic plate small. The molar rows are small (microdont). The older specimens from Mount Nimba (MNHN-ZM-MO-1991-2107) fits well within the variability of the newly collected specimens both from Liberia and Guinea ( Table 8 ). The molar rows are very narrow and relatively small compared to the skull length. When barely worn the big t1 of the upper M1 is isolated from the t2 and t3 and large and round. The t2 and t3 are not well differentiated, fused in a single transverse lobe. The t4 is posterior to the t5 and slightly at the same level as t6. t9 is either very small or absent on both M1 and M2. There are two lobes on the M3 which counts three cusps. On the lower molars, there is a longitudinal link between the prelobe and the first chevron. There is a big posterior cingulum on the m12. The second lobe of the m3 shows traces of two cusps when unworn.