A phylogenetic analysis of the New World tribe Phanaeini (Coleoptera: Scarabaeidae: Scarabaeinae): Hypotheses on relationships and origins

A phylogenetic analysis of Phanaeini based on 137 morphological characters supports the hypothesis that the nine included genera, Coprophanaeus, Dendropaemon, Diabroctis, Homalotarsus, Megatharsis, Oxysternon, Phanaeus, Sulcophanaeus and Tetrameira, form a monophyletic clade. Monophyly is unaffected by the inclusion of Gromphas, Oruscatus, and Bolbites and these should also be considered phanaeines. The sister lineage is Ennearabdus (Eucraniini) and both evolved from ancestral Dichotomiini within South America. There is no support for a close relationship with the Onitini or any other remaining tribe. All phanaeine genera appear to be monophyletic except Sulcophanaeus, of which two species groups appear as sister taxa while the remaining three form an independent paraphyletic clade. Ancestral phanaeines were coprophagous with necrophagy evolving at least twice. Myrmecophily is also derived and most likely evolved only once in the common ancestor of Dendropaemon, Homalotarsus, Megatharsis and Tetramereia. Bare dung ball construction for larval development is also the most likely ancestral condition with a soil covering on the exterior ball surface and parental cooperation evolving in the more derived lineages.