Molecular, morphological and fossil data reveal the Cyrtoquediina (Coleoptera: Staphylinidae: Staphylinini), a new subtribe of rove beetles with multiple biogeographic disjunctions

The rove beetle tribe Staphylinini (Coleoptera: Staphylinidae) is a hyper-diverse group of predatory insects with a global distribution and more than 5,700 described species. This lineage extends back at least to the Early Cretaceous and its members now form dominant components of most terrestrial ecosystems. Recent phylogenetic hypotheses for the tribe suggest that it consists of a monophyletic ‘Staphylinini propria’ clade and a polyphyletic grade of lineages, the latter historically united as ‘Quediina’ by a plesiomorphic shape of the thorax. Most genera of this grade (some consisting of hundreds of species) remain incertae sedis, obscuring 120 million years of evolutionary history. Here we highlight new phylogenetic hypotheses for Staphylinini based on a six loci molecular dataset, densely sampled for members of ‘Quediina’. Our analyses revealed several new lineages, including the subtribe Cyrtoquediina, whose members represent morphologically isolated genera within their respective Neotropical, European and southeast Asian distributions. The Cyrtoquediina are corroborated by a unique morphological character and are hypothesized to be relictual in distribution, due to vicariance: either during the breakup of Laurasia or as a result of climate cooling and polarization, much later in the Oligocene. Recent discoveries of Cyrtoquediina as North American compression (Eocene), and Dominican (Miocene) and Baltic (Eocene) amber fossils provide additional evidence for this hypotheses.