Triassic fossils are rare but crucial for understanding the early evolution of large insect clades including beetles (Coleoptera). Their phylogenetic assignment is problematic because of fragmentary preservation, yet crucial for the correct use of the information they provide. Here an analysis is presented of the phylogenetic position of Leehermania prorova , the Late Triassic compressed fossil which was described and hitherto widely used as the oldest representative of Staphylinidae (rove beetles) in the suborder Polyphaga. By contrast with the intuitive character assessment made in the original description, a phylogenetic analysis of Leehermania is performed using an extensive morphological matrix of extant Coleoptera provided by the Beetle Tree of Life project, constrained in view of the latest relevant molecular phylogenies. As a result, Leehermania is identified as an extinct lineage within the beetle suborder Myxophaga, closest to the modern family Hydroscaphidae. Excluding Leehermania from Staphylinidae and placing it in Myxophaga amends erroneous assumptions about early diversification of rove beetles and enhances our views of the evolutionary history of Coleoptera.

The megadiverse subfamily Staphylininae traditionally belonged to the best-defined rove beetle taxa, but the advent of molecular phylogenetics in the last decade has brought turbulent changes to the group’s classification. Here, we reevaluate the internal relationships among the tribes of Staphylininae by implementing tree inference methods that suppress common sources of systematic error. In congruence with morphological data, and in contrast to some previous phylogenetic studies, we unambiguously recover Staphylininae and Paederinae as monophyletic in the traditional sense. We show that the recently proposed subfamily Platyprosopinae (Arrowinus and Platyprosopus) is a phylogenetic artefact and reinstate Arrowinus as a member of Arrowinini stat. res. and Platyprosopus as a member of Platyprosopini stat. res. We show that several recent changes to the internal classification of the subfamily are phylogenetically unjustified and systematically unnecessary. We, therefore, reestablish Platyprosopini, Staphylinini, and Xantholinini as tribes within Staphylininae (all stat. res.) and recognize Coomaniini as a tribe (stat. nov.) rather than subfamily. Consequently, the traditional ranks of the subtribes Acylophorina, Afroquediina, Amblyopinina, Antimerina, †Baltognathina, Cyrtoquediina, Erichsoniina, Hyptiomina, Indoquediina, Quediina, and Tanygnathinina are restored (all stat. res.). We review the current classification of Staphylininae and discuss sources of incongruence in multigene phylogenies.

Staphylininae is the third largest subfamily of the enormous family Staphylinidae. Monophyly of Staphylininae and its sister relationship to the subfamily Paederinae have been broadly accepted according to both conventional morphology- and molecular-based phylogenies until the last three years. Recent molecular phylogenies rejected monophyly of Staphylininae and regarded Paederinae as a clade within it. This paper re-evaluates the recent molecular work, aiming to clarify the relationship between Staphylininae and Paederinae and resolve intertribal relationships within Staphylininae. Based on a new six-gene data set (5707 bp) for 92 taxa including Oxyporinae (outgroup), representatives of Paederinae, and members of all extant tribes of Staphylininae from published DNA data in GenBank, we generated a well-resolved phylogeny of Staphylininae with all deep nodes (intertribal relationships) strongly supported, and reassert the hypothesis that Staphylininae is monophyletic and indeed the sister group to Paederinae using both Bayesian and maximum likelihood inference. Additionally, our study is a case-study to show that both outgroup selection and completeness of nucleotide data can influence the outcome of a molecular phylogeny. With an increasing number of staphylinid fossils being discovered, the robust phylogeny of Staphylininae inferred by our research will provide a good framework for understanding the early evolution of this group.

Experimental research on beetle responses to removal of logging residues following clearcut harvesting in the boreal balsam fir forest of Quebec revealed severa

Rove beetles of the Staphylinine group of subfamilies represent the most species-rich clade of Staphylinidae, which in turn is the most speciose beetle family. While several relationships within the Staphylinine group are well supported by morphological and molecular data alike, the basal relationships within the clade remain unresolved. In particular, understanding the largest radiation on the beetle tree of life is complicated by the absence of early-diverging transitional fossils. Here we describe a new genus and species of the Staphylinine group of subfamilies from the Lower Cretaceous Yixian Formation in eastern China (c. 125 Ma). Paroxyporus fossilis Cai gen. et sp. nov. shares a number of characters with the monogeneric subfamily Oxyporinae, namely its prognathous head with prominent apically curved mandibles, contiguous procoxae, moderately separated mesocoxae and abdominal intersegmental membranes with a ‘brick-wall’ pattern. It, however, shares oval procoxae and ‘U’-shaped abdominal impressions with the monogeneric subfamily Megalopsidiinae. A parsimony analysis of 211 morphological characters recovered Paroxyporus gen. nov. as sister to the whole Staphylinine group except Oxyporinae, linking Oxyporinae and other clades of the Staphylinine group, and it seems to be a stem member of the Staphylinine group. As such, Paroxyporus gen. nov. may represent an early-diverging isolated lineage within the Staphylinine group, a lineage that has been recognized on the basis of morphological data but challenged by some recent molecular studies, or alternatively a stem member of the Staphylinine group. Together with described fossil members of the subfamily Oxyporinae, Paederine and Staphylinine from the Yixian Formation, Paroxyporus fossilis gen. et sp. nov. is one of the earliest representatives of the Staphylinine group in the fossil record, providing an important calibration point for understanding the timing of the early diversification of rove beetles in the Mesozoic. http://zoobank.org/urn:lsid:zoobank.org:pub:40F8F256-7E9F-478E-AC96-1EB1BCE5A02B