A necro-coprophagous new genus tha is widespread in the whole Sub-Saharan Africa was identified within the tribe Onthophagini and named Tiaronthophagus n.gen. The new genus, which is well characterized by an exclusive set of characters, comprises, at present, 26 species. Twenty species were formerly included in the genus Onthophagus and six were identified and here described as new species: Tiaronthophagus angolensis n.sp., T. jossoi n.sp., T. katanganus n.sp., T. rolandoi n.sp., T. saadaniensis n.sp., and T. zambesianus n.sp. A phylogenetic analysis that is based on a combined matrix, including discrete and landmark characters, was done. The landmark characters were tested using the geometric morphometrics techniques before their inclusion in the matrix. One single, fully resolved tree was obtained, with Tiaronthophagus constituting a distinct, monophyletic clade within Onthophagini, which was clearly separated from the other genera examined here. The biogeographical analysis identified the Central Africa as the ancestral area of the new genus and it mainly accounted for dispersal events leading to the present distribution. The generic rank that is assigned to the taxon is supported by the results of the morphological, phylogenetic, and biogeographical analyses, and by the comparison to the outgroups.