Génier, F. 2026. Three new species of Onthophagus Latreille, 1802 from Bioko Island, Equatorial Guinea, belonging to d’Orbigny’s group IX, with a taxonomic note on O. denudatus d’Orbigny, 1902 (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini). Zootaxa. 5831, 3 (Jun. 2026), 413–426. DOI:https://doi.org/10.11646/zootaxa.5831.3.6.