Myotis Vol. 40 95 - 126 Bonn, December 2002 A revision of the Rhinolophus maclaudi species group with the description of a new species from West Africa (Chiroptera: Rhinolophidae) Jakob F a h r , Henning V i e r h a u s , Rainer H u t t e r e r & Dieter K o c k Abstract. Rhinolophus ziama n. sp. from the Upper Guinea highlands in Guinea and Liberia is de- scribed. This new taxon differs from R. maclaudi in being significantly smaller in size, and from R. ru- wenzorii and R. hilli by skull shape and noseleaf morphology. These four related species are allocated to the formally established R. maclaudi group. A published record of R. maclaudi from Nigeria is here re-identified as R. hildebrandtii and represents the first record for West Africa. R. ruwenzorii is re- ported for the first time from Rwanda. We discuss the biogeography of the species group and propose that its members might represent an ancient radiation now restricted to two disjunct refuges in the Up- per Guinea highlands and the mountain range along the Albertine Rift. This pattern strikingly resem- bles that of Micropotamogale lamottei and M. ruwenzorii (Tenrecidae). The conservation status of the four species is discussed and updated IUCN Red List categories are proposed. It seems likely that these species are seriously threatened both by habitat degradation within their small distribution ranges and direct exploitation in their day roosts. Key words . Africa, biogeography, Chiroptera, conservation, distribution, first records, Ethiopian Region, evolution, new species, Rhinolophidae, taxonomy. Introduction The West African Rhinolophus maclaudi Pousargues, 1897 has its noseleaf characteristi- cally structured: a broad and forward-inclined sella with large basal lobes forming a heart-shaped cup, almost completely covering the nostrils, the connecting process only weakly developed and low, leaving a deep emargination between the sella and the lancet, and the nostrils bordered on each side by a more or less straight rim. The skull is charac- terized by its slenderness and a heavy rostrum. The interpterygoid pit is barrel-shaped and unusually deep. Two closely related taxa were discovered in the region of the Albertine Rift, i.e. R. ruwenzorii J. Eric Hill, 1942 and R. hilli Aellen, 1973. These three species were re- viewed by Smith & Hood (1980). They considered all described character differences in morphology and size of these taxa as being of no particular significance. Therefore, they