Phylogenetic relationships of the intertidal genus Halorhadinus Sawada and key to the genera of the Liparocephalini (Coleoptera: Staphylinidae: Aleocharinae)

Abstract

AbstractHalorhadinus Sawada is redescribed and illustrations of diagnostic features are presented. Median lobes and parameres of H. aequalis Sawada and H. inaequalis Sawada are described for the first time. A key is provided for separation of the known species of Halorhadinus. Based on contiguous mesocoxal cavities, galea with several setae only on mesal surface and apex with setae, Halorhadinus is hypothesized to be a member of the tribe Liparocephalini. A revised cladistic analysis of the Liparocephalini based on 50 adult characters suggests that Halorhadinus belong to the Liparocephalini with the following patterns of generic relationships (outgroup (Salinamexus Moore & Legner (Halorhadinus Sawada (Amblopusa Casey (Paramblopusa Ahn &Ashe (Diaulota Casey + Liparocephalus Mäklin)))))). Monophyly of the genus Halorhadinus is supported by three synapomorphies (mentum with anterior margin deeply sinuate and antero-lateral parts triangular; ligula round and very long, almost reaching to half of palpi; spatulate setae mostly located on basal part of palpi). A key to the genera of the Liparocephalini is given.