Three morphological datasets (traditional measurements, dorsal and ventral skull shape coordinates) were used to examine craniometric variation in the water rat Dasymys, a genus found throughout sub-Saharan Africa. This study is the first to examine the entire genus as well as to statistically compare taxa within the genus to the nominate species D. incomtus. Morphological data confirmed that the five species recognised by Musser & Carleton (1993); D. incomtus, D. foxi, D. nudipes, D. montanus and D. rufulus, represent valid morphological species although two of the species do not encompass the geographic areas presently assigned to them. Dasymys rufulus occupies a larger range and D. incomtus a much smaller range than previously suggested with D. rufulus appearing to be part of a species complex. Furthermore, we discerned six additional morphological species resulting from the elevation of four subspecies (D. i. capensis, D. i. griseifrons, D. i. medius and D. i. longipilosus) and the recognition of two new species: D. shortridgei (restricted to the Okavango Delta) and D. robertsii (occurring in the Limpopo and Mpumalanga Provinces of South Africa).
Copyright 2004, Walter de Gruyter