Morphological phylogeny and biogeography of the Pterostichus raptor species group (Coleoptera: Carabidae) of ground beetles, endemic to the Korean Peninsula and adjacent islands

To investigate the history of differentiation of the Pterostichus raptor species group of carabid beetles, endemic to the Korean Peninsula and adjacent islands, we performed cladistic analyses based on 30 adult morphological characters for all 12 species of the group and an outgroup species. The resultant tree revealed three monophyletic clades within the group, each of which is composed of 3–6 parapatric or allopatric species; the three clades occur sympatrically in most parts of the peninsula. Reconstructions of geographic range history on the obtained tree showed that the initial divergence of the three clades occurred in the Taebaek Mountains and that each clade subsequently dispersed southward and speciated after that dispersal.