Early evolution of the hyperdiverse rove beetle tribe Staphylinini (Coleoptera: Staphylinidae: Staphylininae) and a revision of its higher classification.

The rove beetle tribe Staphylinini (Staphylinidae: Staphylininae) is a monophyletic lineage of over 5500 relatively large and charismatic species, yet its higher classification remains deeply rooted in historical concepts. Despite recent progress toward inferring phylogenetic relationships within this group using morphological and molecular datasets, relationships among taxa that were united under a polyphyletic "Quediina" remain largely unknown. To infer these relationships, we analysed a six-gene dataset (4370 bp) using parsimony and model-based analyses and the results were placed in the context of morphology. While all genes contributed synapomorphies for major lineages or relationships between them, carbamoyl synthetase (CAD), topoisomerase I (TP) and wingless (Wg) were the most informative. TP was generally most informative at the level of subtribe, Wg above this level and CAD throughout the tree. The monophyly of Staphylinini was strongly supported and analyses support seven clades that correspond to higher taxonomic levels, four of which are formally described as subtribes here: Acylophorina stat. rev., Cyrtoquediina new subtribe, Erichsoniina new subtribe and Indoquediina new subtribe. The majority of Staphylinini taxa were recovered within a well-supported "northern hemisphere clade" that is weakly represented in the southern hemisphere. The composition and morphological diagnosis of the "Staphylinini propria" clade are revised, and the pronotum shape historically associated with this group is shown to have evolved multiple times elsewhere in Staphylinini. The genus Stevensia is moved from Staphylinina to Acylophorina based on morphological evidence. Cyrtoquedius stat. nov., previously a subgenus of Quedius, is raised to the genus level. The following 32 new combinations (from Quedius) are proposed: Cyrtoquedius anthracinus (Solsky); C. arrogans (Sharp); C. basiventris (Sharp); C. bolivianus (Sharp); C. bruchi (Bernhauer); C. clypealis (Sharp); C. concolor (Sharp); C. flavicaudus (Sharp); C. flavinasis (Bernhauer); C. frenatus (Erichson); C. graciliventris (Sharp); C. jacobi (Scheerpeltz); C. jocosus (Sharp); C. labiatus (Erichson); C. laeviventris (Bernhauer); C. mexicanus (Sharp); C. ochropygus (Bernhauer); C. ogloblini (Bernhauer); C. ornatocollis (Bierig); C. protensus (Sharp); C. rufinasus (Sharp); C. verecundus (Sharp); C. verres (Smetana); Indoquedius borneensis (Cameron); I. dispersepunctatus (Scheerpeltz); I. javanus (Cameron); I. malaisei (Scheerpeltz); I. micantiventris (Scheerpeltz); I. parallelicollis (Scheerpeltz); I. philippinus (Cameron); I. recticollis (Scheerpeltz); and I. sanguinipennis (Scheerpeltz). Cyrtoquedius verres is recorded from the state of Georgia (USA) for the first time, which, together with its transfer from Quedius, extends the distribution of the Cyrtoquediina significantly northward into the Nearctic.