Insights for the subtribal-level phylogenetic reconstructions in Paederinae (Coleoptera: Staphylinidae): a study on mesoventral plate with elements of comparative morphology

Morphological characters are one of the bases for describing any organismal group and comparative morphology plays an important role in taxonomy, systematics, and evolutionary research. Yet, in many groups, especially highly diverse, the terminology and homology of morphological structures are poorly understood. One of such examples is the mega-diverse group of animals, rove beetles (Staphylinidae), where comparative studies are very rare, both across the subfamilies and within them. In this paper, we present our results of morphological examination of mesoventral sclerotisation across different subtribes and genera of Paederinae, which is one of the most diverse rove beetle subfamily. Additionally, we compare them with several representatives of Staphylininae and Xantholininae. We revise morphological terminology for the mesoventral area in Paederinae and propose a hypothesis for character homologisation within Paederinae and across the listed subfamilies. Our results are based on examination of representatives of 157 Paederinae genera and the major groups are illustrated by schematic drawings and SEM scans. Additionally, we introduce new characters with potential importance for subtribal level phylogenetic reconstruction of Paederinae relationships. This is the first comprehensive review of the mesoventral area for the subfamily.