Otomys cuanzensis Hill and Carter 1937

Otomys cuanzensis Hill and Carter 1937, Am. Mus . Novit., 913: 7.

Type Locality: Angola, Chitau, 4930 ft.

Vernacular Names: Cuanza Vlei Rat.

Distribution: C Angola; limits uncertain.

Discussion: Described as a species, but Bohmann (1952) drew it within his polytypic interpretation of O. irroratus, its usual allocation thereafter (Crawford-Cabral, 1986; Ellerman et al., 1953; Meester et al., 1986; Misonne, 1974). Musser and Carleton (1993) mistakenly aligned cuanzensis as a synonym of O. maximus, but its affinity lies with O. irroratus proper, as appreciated by Crawford-Cabral (1986). Hill and Carter’s (1937) specific description is terse, contrasting cuanzensis solely with Angolan populations of the very different form maximus, not irroratus in the strict sense. The holotype (AMNH 85841) and referred specimens (AMNH series) of cuanzensis approximate O. irroratus in overall size and uniformly possess a six-laminated M3 and large stapedial foramen; however, they differ from O. irroratus in their predominantly brown dorsal pelage and narrower nasals, a contrast also remarked by Bohmann (1952). In view of such differences, the apparently wide geographic hiatus from southern African O. irroratus, and the pronounced karyotypic and genetic substructuring known for even contiguous populations of the latter (e.g., Contrafatto et al., 1997; Taylor, 2000 b), we retain cuanzensis as species until its relationships and status can be critically assessed.