Gunter, N. L. | bioRxiv Science

bioRxiv2026

Phylogenomics resolves a 200-year-old puzzle: a revised tribal classification of Afro-Eurasian dung beetles (Coleoptera: Scarabaeinae)

BackgroundThe tribal classification of scarab dung beetles (Coleoptera: Scarabaeinae) is currently largely incomplete due to the lack of robust phylogenetic evidence supporting the assignment of many Afro-Eurasian and American genera to tribes. MethodsWe used ultraconserved elements (UCEs) to infer phylogenetic relationships across most Afro-Eurasian dung beetle lineages, including 25 of the 27 extant genera currently incertae sedis. ResultsWe recovered full support for the monophyly of previously recognised tribes and for several phylogenetically and morphologically clearly delimited new tribal-level clades, allowing us to propose a complete tribal classification for all Afro-Eurasian dung beetle genera. Thirteen new tribes are described and diagnosed: Aphengoecini trib. nov., Bohepilissini trib. nov., Catharsiini trib. nov., Chalconotini trib. nov., Circelliini trib. nov., Dwesasilvasedini trib. nov., Haroldiini trib. nov., Heliocoprini trib. nov., Janssensantini trib. nov., Macroderini trib. nov., Nesovinsoniini trib. nov., Pycnopanelini trib. nov. and Tanzanolini trib. nov. The tribe Coprini sensu novo is redefined as comprising three subtribes: Coprina, Onychothecina subtrib. nov. and Pedariina subtrib. nov. The tribe Odontolomini is downranked to a subtribe of Endroedyolini sensu novo, becoming Endroedyolini Odontolomina stat. nov. The tribe Onthophagini sensu novo is redefined and divided into three subtribes: Helictopleurina stat. nov., Oniticellina stat. nov. and Onthophagina; the remaining former subtribes of Oniticellini (Attavicinina, Drepanocerina and Liatongina) are synonymised with Oniticellina; the subtribe Alloscelina of Onthophagini is synonymised with Onthophagina (syn. nov.). The tribe Panelini stat. rev. and sensu novo, comprising the single genus Panelus, is revalidated and redefined. Updated morphological diagnoses of Elassocanthonini, Gymnopleurini, Onitini and Scarabaeini are provided. The genus Phaedotrogus is synonymised with Haroldius (Haroldiini) (syn. nov.). An identification key to all Afro-Eurasian dung beetle tribes is provided. DiscussionOur results establish a robust phylogenetic framework and revised tribal classification for Afro-Eurasian Scarabaeinae dung beetles, providing a foundation for future taxonomic, comparative and macroevolutionary research.

zoology↗

bioRxiv2023

A transcriptome-based phylogeny of Scarabaeoidea confirms the sister group relationship of dung beetles and phytophagous pleurostict scarabs (Coleoptera)

Scarab beetles (Scarabaeidae) are a diverse and ecologically important group of angiosperm-associated insects. As conventionally understood, scarab beetles comprise two major lineages: dung beetles and the phytophagous Pleurosticti. However, previous phylogenetic analyses have not been able to convincingly answer the question whether or not the two lineages form a monophyletic group. Here we report our results from phylogenetic analyses of more than 4,000 genes mined from transcriptomes of more than 50 species of Scarabaeidae and other Scarabaeoidea. Our results provide convincing support for the monophyly of Scarabaeidae, confirming the debated sister group relationship of dung beetles and phytophagous pleurostict scarabs. Supermatrix-based maximum likelihood and multispecies coalescent phylogenetic analyses strongly imply the subfamily Melolonthinae as currently understood being paraphyletic. We consequently suggest various changes in the systematics of Melolonthinae: Sericinae Kirby, 1837 stat. rest. and sensu n. to include the tribes Sericini, Ablaberini and Diphucephalini, and Sericoidinae Erichson, 1847 stat. rest. and sensu n. to include the tribes Automoliini, Heteronychini, Liparetrini, Maechidiini, Scitalini, Sericoidini, and Phyllotocini. Both subfamilies appear to consistently form a monophyletic sister group to all remaining subfamilies so far included within pleurostict scarabs except Orphninae. Our results represent a major step towards understanding the diversification history of one of the largest angiosperm-associated radiations of beetles.

zoology↗