We conducted morphological and DNA barcoding analyses of representative taxa in the Mecynorhina Hope, 1837 species-complex (type species: Scarabaeus polyphemus Fabricius, 1781), which had been split into five subgenera by DE PALMA & FRANTZ (2010). Subgenus Mecynorrhinella Marais and Holm, 1992 (type species: Mecynorhina oberthuri Fairmaire, 1903), comprising taxa with a simple, saber-shaped horn, is here raised to genus level (stat. rev.) to receive four species: Mecynorrhinella torquata (Drury, 1782), Mecynorrhinella immaculicollis (Kraatz, 1890) stat rev., Mecynorrhinella poggei (Kraatz, 1890) stat. rev. (=ugandensis Moser, 1907 syn. nov.), and Mecynorrhinella oberthuri. Mecynorhina is found to involve two distinct species with bifurcate horn: Mecynorhina polyphemus from West Africa and Mecynorhina confluens Kraatz, 1890 stat. rev. from Central Africa. Chelorhinella De Palma & Frantz, 2010 (type species: Mecynorhina savagei Harris, 1844) is raised to genus level (stat. rev.) to accommodate Chelorhinella kraatzi (Moser, 1905) and three highly similar members in the savagei species-group. In addition, Amaurodes Westwood, 1843 (type species: Ceratorhina (Amaurodes) passerinii Westwood, 1843) is raised to genus level (stat. rev.) and Megalorhina Westwood, 1847 (type species: Ceratorhina (Megalorhina) harrisii Westwood, 1847) is ranked subgenerically under it (comb. nov.). The resulting four genera display markedly different aedeagal types, strongly supporting their generic status. Finally, Ceratorhinella De Palma, Takano, Léonard & Bouyer, 2021 (type species: Eudicella cupreosuturalis Bourgoin, 1913), which was previously ranked subgenerically under Eudicella White, 1839 (type species: Cetoninus (Goliathus) smithii MacLeay, 1838), is now raised to genus level (stat. rev.). Interestingly, Mecynorhina, Chelorhinella, Amaurodes, Ceratorhinella and Eudicella-all Goliathini with bifurcate horns-form a separate clade that is sister to Mecynorrhinella. These findings, while limited to the analysis of a single mitochondrial gene, suggest that the simple horn of Mecynorrhinella, which is unique among the African Goliathini, has evolved from a precursor near to Mecynorhina before, or in parallel to, the radiation and diversification of allied Goliathini with bifurcate horns.
