Deschodt, Christian M.Davis, Adrian L.V.Scholtz, Clarke H.2015-05-292015-05-292015-04Deschodt, CM, Davis, ALV & Scholtz, CH 2015, 'A new synonymy in the fidius group of Copris Müller 1764 (Coleoptera: Scarabaeidae : Scarabaeinae) and a new species from the highland grasslands of South Africa', Zootaxa, vol. 3949, no. 3, pp. 431-438.1175-5326 (print)1175-5334 (online)10.11646/zootaxa.3949.3.8http://hdl.handle.net/2263/45340The fidius group constitutes the basal clade in a phylogeny of the Afrotropical members of the genus, Copris Müller, 1764. In this paper we describe Copris crassus Deschodt and Davis as a new species in this group. We also demonstrate that the distributional function between two body dimensions (lateral horn length and mid-line elytron length) differs between Copris fidius (Olivier 1789) and C. crassus. Copris bihamatus Balthasar, 1965 is also a member of the fidius group. Nguyen- Phung (1988) suspected that it was a synonym of C. fidius (Olivier) so we compare specimens of similar body size and use the distributional function between body dimensions to demonstrate that C. bihamatus is indeed a synonym of C. fidius. We provide a key for all known valid species in the fidius group, except C. serius Nguyen-Phung, 1987.en© 2015 Magnolia PressScarabaeidaeScarabaeinaeNew speciesCoprisCrassusFidiusBihamatusEndemicNew synonymPreprint Article