Dasymys, Peters, 1875

Denys, Christiane, Missoup, Alain Didier, Nicolas, Violaine, Fülling, Olaf, Delapré, Arnaud, Bilong, Charles Felix Bilong, Taylor, Peter John J. & Hutterer, Rainer, 2014, African highlands as mammal diversity hotspots: new records of Lamottemys okuensis Petter, 1986 (Rodentia: Muridae) and other endemic rodents from Mt Oku, Cameroon, Zoosystema 36 (3), pp. 647-690 : 666-667

Dasymys sp.

MATERIAL EXAMINED. — MNHN: 1984-498, 2011-902 to 2011-909; 2011-928.

ZFMK: 91.221, 2003-902 to 2003-904.

ZFMK: Owl pellets Oku Cave: 91.97 to 91.101.

Morphological characters Dasymys incomtus longipilosus Eisentraut, 1963 was initially reported on Mt Cameroon at around 2200 m. The author pointed out its long hair. This species is also found on Mt Manengouba. Fülling (1992) named the specimens he trapped on Mt Oku D. cf. rufulus . According to Rosevear (1969), D. i. longipilosus has a smaller hindfoot (about 26 mm) than D. rufulus and D. foxi (about 28.5 mm for D. rufulus and 31 mm for D. foxi ). According to Mullin et al. (2004) the small size of the skull, the dark pelage and the short tail characterize D. longipilosus . We compare our newly collected specimens to D. longipilosus of Mt Cameroon. The specimens of Mt Cameroon are darker and the hairs are longer. In the ventral view, the skull of D. longipilosus exhibits a long incisive foramen extending far between the molar rows, while in D. sp. and D. rufulus from West Africa it end before the molar rows. External measurements of eight of the nine new specimens trapped in Mt Oku are presented in Table 7.

According to Rosevear (1969) all D. rufulus have a TL/HB ratio of 99% while this value reaches 98 % for D. foxi and 95% for D. longipilosus from Mt Cameroon. The HF of Mt Cameroon specimens are clearly smaller, as with the TL/HB ratio. The holotype of D. longipilosus is an adult with a short HF (24 mm) and a TL/HB ratio of 91 %. The Mt Oku specimens have a shorter TL/HB ratio of 94 % (mean), a greater HF (30 mm) and a HB of 131 mm. These measurements are similar to those of D. foxi specimens from Panyam ( Rosevear 1969). However, the TL of Oku specimens is very short (122.6 mm in average) and significantly smaller than the HB (mean: 94 %, Min: 87%, Max: 101 %). We thus consider the specimens of Oku as belonging to a distinct, possibly undescribed species.