Canthidium trinodosum

Canthidium trinodosum (Boheman, 1858) Onthophagus trinodosus Boheman, 1858: 46. Type locality: Brazil: Rio de Janeiro. Name-bearing type: a single known syntype (NHRS), examined by FZVM. Note: Boheman’s name is a junior primary homonym of Onthophagus trinodosus Fåhraeus, 1857. Both names are currently in use, the former for a South American species treated in the genus Canthidium since Harold (1867b), the latter for an African species of Onthophagus. Since the two primary homonyms are in use and have not been applied to taxa considered congeneric after 1899, the junior homonym must not be automatically replaced as it would be in other situations. The case must instead be referred to the Commission under Article 23.9.5 for a ruling. In the meantime, current usage is maintained. Onthophagus subarmatus Harold, 1862: 403 (new replacement name for Onthophagus trinodosus Boheman, 1858 due to its junior primary homonymy with O. trinodosus Fåhraeus, 1857). Type locality and name-bearing type: the same as for Onthophagus trinodosus Boheman in accordance with Article 72.7. Note: when Harold (1862) established this nomen novum, the species was still treated in Onthophagus. However, five years later, after seeing “the type specimen”, Harold (1867b) transferred it to Canthidium and resurrected the replaced name, invalidating his own nomen novum. He did so because, in his view, the homonymy had been undone once the species was transferred to another genus and, therefore, nothing prevented Boheman’s name from being used. This is not the interpretation of the current Code: primary homonymies are not undone even if the homonyms are no longer applied to congeneric taxa; the junior homonym is, with a few exceptions, permanently invalid according to Article 57.2 and a substitute name should be adopted following Article 60. But since, in this case, as explained above, the junior primary homonym is in prevailing usage in a different genus as that of its senior homonym, Harold’s decision should be respected until the Commission rules on the case. Distribution Brazil (Cupello 2018). Literature record Roze 1955: 44 (cited for Aragua).