Taxonomic revision of the South American dung beetle genus Gromphas Brullé, 1837 (Coleoptera: Scarabaeidae: Scarabaeinae: Phanaeini: Gromphadina).

As defined here, Phanaeini comprises two subtribes, Gromphadina, with Gromphas and Oruscatus, and Phanaeina, with 10 genera including Bolbites. Gromphas occurs east of the Andes and includes five species: G aeruginosa (Perty, 1830) (= G lacordairei Blanchard, 1846); G amazonica Bates, 1870; G. dichroa Blanchard, 1846; G inermis Harold, 1869 (= G. lacordairii Burmeister, 1874; G. lacordairei bipunctata d'Olsoufieff, 1924, new synonymy); and G. lemoinei Waterhouse, 1891. Brullé (1837) never mentioned or described "G. larcordairei" and all citations to "G lacordairei Brullé" refer in fact to G. larcordairii Burmeister, ajunior objective synonym of G. inermis Harold. The first author to include species in Gromphas was Blanchard (1846), and one of these species, G. dichroa Blanchard, is here designated as the type species of Gromphas. Gromphas lemoinei Waterhouse is here revalidated and is distinguished from G. aeruginosa (Perty) mainly by the shape of the pronotal prominence. Lectotypes are designated for G. amazonica, G. inermis, and G. lacordairei bipunctata. Redescriptions of the genus and its species, an identification key and a distribution map are presented, as well illustrations of all species, including the type specimens of G. aeruginosa, G. lemoinei, and G. amazonica.