Early evolution of the beetles

Beetles comprise the largest of the holometabolous insect orders and have flourished in nearly every terrestrial habitat. As part of the NSF-funded “Assembling the Beetle Tree of Life” project, we report recent phylogenetic findings on deep relationships within the Coleoptera. Eight nuclear genes sampled across 120 taxa and analyzed in a variety of Bayesian and likelihood approaches support monophyly of the existing suborders but differ from some previous schemes in recovering a sister relationship between the two largest suborders, Adephaga and Polyphaga. Several polyphagan lineages whose taxonomic placement has been contentious, including Scirtoidea and Derodontidae, emerge basally within the suborder. We also discuss the dates and timing of early events in Coleopteran evolution.