Eureka: discovery of male Turgiditarsus Schillhammer reveals its placement in Acylophorina and resolves phylogenetic relationships within the subtribe (Coleoptera: Staphylinidae: Staphylininae)

Turgiditarsus Schillhammer comprises some of the most bizarre and rarely encountered rove beetles in the subfamily Staphylininae. The genus is presently known from only 4 female specimens comprising three species in the eastern Oriental region. Its previous placement in Anisolinina was based primarily on superficial similarity, much before recent advances in the systematics of tribe Staphylinini. Total evidence phylogenetic analysis of a broad taxon sample within Staphylinini, including the first male specimen of Turgiditarsus, revealed that the genus should be placed in the morphologically diverse and relictual Acylophorina, a subtribe with one of the oldest crown group ages in the latest Early Cretaceous. Turgiditarsus is redescribed and two new species, T. eureka Schillhammer and Brunke sp.n. and T. vietnamensis Schillhammer and Brunke sp.n., are described, bringing the total number to five. Amacylophorus Smetana stat.n., a subgenus of Acylophorus Gravenhorst, is raised to genus rank and redescribed, with the following new combination: Amacylophorus pratensis (LeConte) comb.n. Stevensia Cameron and its single species, recently moved to this subtribe, are redescribed. All genera of Acylophorina are diagnosed and included in a novel world key. A species level key is updated for Turgiditarsus. Further systematic work within diverse Acylophorus is needed to re-assess the status of Acylohsellus, Paratolmerus and the remaining subgenera of Acylophorus