New Britain Island Uromys

description

Description. The holotype (and only known) skin and skull are in good condition. The overall colour is TODO TODO TODO TODO TODO TODO TODO TODO TODO foreparts and with a lighter sheen on the hindparts. The pelage consists largely of long, dark guard hairs, somewhat paler towards the base, with a few light-coloured guard hairs and crimped grey-white underhairs mixed in. The venter is sparsely furred, with the lighter skin tone showing through; the ventral hairs are mostly brown, but there is a sharply marked creamy-white streak, 92 mm long, in the midline of the chest, along the approximate extent of the sternum, beginning as a thin streak at about the level of the axillae, broadening suddenly 22 mm further back, and narrowing gradually behind (Fig. 8). Hands and feet are lighter brown owing to the sparseness of the hair covering; vibrissae are long and black. The tail scales are somewhat longer than broad, flattened, and arranged in rings. The skull is deep, especially the rostrum, as in U. anak and U. neobrittanicus, but unlike these the nasals are relatively short, and the postorbital processes are only slightly developed. The parietal crests are well developed, extending forward

A revision of the genus Uromys Peters, 1867 (Muridae: Mammalia) with descriptions of two new species

description

Relationships. Uromys neobrittanicus is clearly the sister species to U. anak, from which it differs in a few skull characters and in colour; of these it is likely that the condition seen in the present species is the plesiomorphic one, with the exception of the striking postorbital processes (a gross enlargement of the small tubercles of U. anak), and the more numerous tail scales Uromys boeadii n. sp. Figs 8, 9, Table 2

A revision of the genus Uromys Peters, 1867 (Muridae: Mammalia) with descriptions of two new species

diagnosis

Diagnosis. This new species is phenetically closest to the U. anaklU. neobrittanicus group, agreeing with the members of this group in its uniformly black tail, the deep rostrum, the tendency towards development of distinct postorbital processes, and the posteriorly extended nasal bones. It differs from them in the following ways: i) size much smaller; ii) postorbital processes poorly developed; iii) posterior ends of nasal bones only just reaching level of anterior orbital margins; iv) tail scales longer than broad, and arranged in clear rings. It differs additionally from U. anak as follows: i) lack of prominent inflation of frontotemporal sutures; ii) flat interorbital area. It differs from U. neobrittanicus as follows: i) less tail scales (7 - 9 per cm oflength); ii) deep blackbrown colour with sharply marked median pectoral streak.

A revision of the genus Uromys Peters, 1867 (Muridae: Mammalia) with descriptions of two new species

diagnosis

Revised diagnosis. Uromys (u.) neobritannicus differs from all other species of Uromys as follows: i) hypertrophy of the postorbital processes; ii) uniformly black tail (otherwise in subgenus only in U. anak and U. boeadii n. sp., from which it also differs by much larger postorbital processes, square posterior ends of nasals which do not extend as far posteriorly, reddish body colour with deep yellow venter, and more numerous tail scales [16 per cmD; iii) unlike U. anak, but like U. boeadii n. sp., there are no swollen vertical ridges below postorbital processes, despite the large size of the processes; iv) one of the largest species, equal in size to U. anak.

A revision of the genus Uromys Peters, 1867 (Muridae: Mammalia) with descriptions of two new species