Phylogeny and Evolution of the Genus Abax : A Genetic and Biosystematic Approach (Carabidae, Pterostichini)

In this article, we carry out a study of the genus Abax (Carabidae, Pterostichini) based on mitochondrial and nuclear markers to test hypotheses about its evolutionary history in an integrative taxonomical framework. The subgenera Pterostichoabax (four species) and Abacopercus (monotypic) are likely natural taxa supported by all data. Pterostichoabax was nested within the species of the nominal subgenus Abax , which is rendered polyphyletic. The subgenus Abax is subdivided into a few clades that include two or more taxa and correspond to monophyletic lineages. The subdivisions within Abax parallelepipedus and Abax pyrenaeus are related to the geographical origin and may correspond to current subspecies. The results support hypotheses about a close relationship within the species of the POBE group ( A. pilleri , A. oblongus , A. baenningeri , and A. exaratus ); between A. carinatus , A. pyrenaeus , and A. parallelus ; the basal position of A. schueppeli ; and the monophyly of Pterostichoabax . In contrast, hypotheses about a close relationship between the species pairs schueppeli ‐ carinatus , parallelepipedus ‐ fiorii , and ovalis ‐ parallelus were not supported by molecular results. The evolutionary history of Abax has been traced back to the Middle Tortonian (10.3 MYA). Successive lineage splits during the second half of the Miocene gave rise to the main lineages, with rapid intraspecific radiation during the Pleistocene. Lineage diversification included moderate ecological, behavioral, and molecular changes accompanied by morphological conservatism and diversified geographical patterns. Our results constitute a framework for future studies on the evolutionary radiation of the genus Abax and other carabids during the Miocene in the western Palearctic and contribute to developing a natural classification of the genus.