Subfamily Aclopinae Recent studies indicate that the Aclopinae as previously considered does not constitute a monophyletic group (Smith et al. 2006; Ocampo et al. 2010). In a recent publication, Ocampo and Vaz-de-Mello (2008) excluded the Bornean genus Xenaclopus from the Aclopinae and placed it within Melolonthinae incertae sedis, because further studies are needed to reliably place this genus in the context of the melolonthine classification. Although the protruding labrum and mandibles are characters shared with the other genera currently placed in the subfamily Aclopinae, there is no evidence that supports that these characters are synapomorphic and are likely due to convergence. As a result of this study, we have removed both Phaenognatha and Neophaenognatha from the Aclopinae and place them in the tribe Phaenognathini within the subfamily Melolonthinae. The relationships of this tribe with other melolonthine tribes are uncertain. The most obvious difference between these genera and aclopines is the presence of a well developed genital capsule (the genital capsule is absent in aclopines). These data, along with morphological evidence, supports the hypothesis of a relationship between Phaenognatha and Neophaenognatha and the Chilean Lichniini (currently in Melolonthinae), and they together might constitute a distinct and ancient lineage of Scarabaeidae.

Published as part of Ocampo, Federico C. & Mondaca, José, 2012, Revision of the scarab subfamily Aclopinae Blanchard (Coleoptera: Scarabaeidae) in Argentina and Chile, pp. 1-29 in Zootaxa 3409 on page 3, DOI: 10.5281/zenodo.210632