BIOLOGIE, 77: 23-75, 2007 BIOLOGIE, 77: 23-75, 2007 BULLETIN DE L’INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE BULLETIN VAN HET KONINKLIJK BELGISCH INSTITUUT VOOR NATUURWETENSCHAPPEN † Walter VERHEYEN and Marco CONTI passed away before this study was completed. This study is dedicated to them. The characterization of the Kilimanjaro Lophuromys aquilus TRUE 1892 population and the description of ive new Lophuromys species (Rodentia, Muridae) by Walter N. VERHEYEN † , Jan L. J. HULSELMANS, Theo DIERCKX, Loth MULUNGU, Herwig LEIRS, Marco CORTI † & Erik VERHEYEN Abstract We revised the taxonomy of the Lophuromys lavopunctatus species complex based on craniometric measurements of > 3000 specimens and cytochrome b sequences of selected specimens collected throughout East Africa. Our approach, that consists of measuring skulls of a series of localities (topo-typical if possible), allowed us to compile a number of Operational Taxonomical Units (OTU’s) from across the geographic range of this species complex. The outcome of diverse multivariate analyses complemented with the available chromosomal data allowed us to (a) evaluate the craniometrical and genetic variation within this dataset, (b) to provide a more detailed characterisation of Lophuromys aquilus and laticeps, and (c) to identify ive OTU’s that are described as new species. Key-words: Rodentia, Africa, Lophuromys, taxonomy, new species, craniometry, cytochrome b, genetics. INTRODUCTION The genus Lophuromys (TRUE, 1892) represents a peculiar group of mice with a distribution range that is restricted to sub Saharan Africa (MUSSER & CARLETON, 2005). Because of the unique, stiff hairs that make up their pelage, these species are known as ‘brush-furred rats’, ‘harsh-furred rats’ or ‘coarse-haired mice’. These chunky mice have relatively short legs, and while some species can be speckled, the color of their pelage ranges from tan to greenish grey and dark brown. Their belly can be rusty, orange, brown, or even cream colored. In order to facilitate their escape from predators, the tails and the fragile skin of these solitary species break easily. These small mammals thrive in moist habitats. Their geographical distribution appears to be determined by rainfall (density and seasonal pattern) and not by altitude, temperature or biotope structure (KINGDON, 1974; DIETERLEN 1976). Their typical diet consists of ants, other insects and invertebrates, small vertebrates, carrion, and plant matter. It is noteworthy that they appear to feed more on animal matter than most Muridae (DIETERLEN, 1976). The Lophuromys lavopunctatus THOMAS, 1888 s. l. species complex groups the so-called African “speckled brush furred” rats that occur from North-Eastern Angola through Southern Congo, Northern Mozambique, Tanzania, Burundi, Rwanda, Eastern Congo, Northern Congo, Uganda, Southern Kenya and Ethiopia, the latter being separated from the rest of the species complex by dry lowlands (MUSSER & CARLETON, 2005). To date, ifteen species have been described (V ERHEYEN et al., 2002, Appendix 1.1 and Figure 1). The relatively patchy distribution ranges of these species suggest that they probably originated as the result of allopatric speciation. Neighboring regions with suitable moist habitats that are separated by dry corridors, are typically occupied by different species (LAVRENCHENKO et al. this issue). Consistent with the fact that these mammals thrive in moist habitats only, gene low is either absent, or greatly restricted, among these isolated pockets (MUSSER & CARLETON, 2005). The number of recognized species in this genus has increased in recent years and it is likely that the true diversity of this group remains to be discovered (LAVRENCHENKO et al, 1998, 2001, 2004, this issue). The present study builds upon the results of our previous paper on the taxonomy of the East African L. lavopunctatus species complex (V ERHEYEN et al, 2002). In that study we concluded that no satisfactory