Molecular phylogeny and Holarctic diversification of the subtribe Calathina (Coleoptera: Carabidae: Sphodrini)

A molecular phylogeny of the subtribe Calathina was inferred from DNA sequence data from the mitochondrial cox1-cox2 region and the nuclear genes 28S and EF-1a. All lineages within Calathina from the Holarctic region were represented except for the monotypic subgenus Tachalus. Maximum Parsimony and Bayesian analyses of the combined data set showed that the subtribe is a monophyletic lineage that includes a single genus Calathus, where other taxa currently ranked as independent genera (Lindrothius, Synuchidius, Thermoscelis and Acalathus) are nested within this genus. Neocalathus and Lauricalathus, both subgenera of Calathus, were found to be polyphyletic and in need of taxonomic revision. The subtribe appears to have originated in the Mediterranean Basin and thereafter expanded into most parts of the Palearctic region, the Macaronesian archipelagos (at least five independent colonisation events), the Ethiopian highlands and the Nearctic region (at least two independent events).