Taxonomic revision of the Phanaeus chalcomelas species group and a description of the new Phanaeus achilles species group (Coleoptera: Scarabaeidae: Scarabaeinae: Phanaeini)

The Phanaeus chalcomelas species group includes coprophagous and necrophagous South American scarab beetles (Coleoptera: Scarabaeidae) that are widely distributed in the Amazon Basin and along the eastern slopes of the Andes. The group is characterized by the distinctly punctuated elytral striae and the black rugosities on the pronotum. It is composed of five species: Phanaeus chalcomelas (Perty, 1830); P. cambeforti Arnaud, 1982; P. meleagris Blanchard, 1845; P. lecourti Arnaud, 2000 and P. achilles Boheman, 1858. The P .chalcomelas group was revised based on the external morphology and the morphology of the medial endophallite, which are illustrated for the first time. We provide a new diagnosis of the P. chalcomelas group, along with updated geographical distribution maps and diagnosis of previously described species. The P. chalcomelas species group now comprises seven species: two new species described herein, one revalidated, and four previously described: P. cambeforti, P. chalcomelas, P. lecourti, P. meleagris, P. minos Erichson, 1847 stat. rev., P. divisor sp. nov., and P. mariocupelloi sp. nov. Based on morphological evidence and previous molecular studies, we propose the new Phanaeus achilles species group to include: P. achilles, P. arnaudorum sp. nov., and the subfossil species P. violetae Zunino, 2013.