Revision of the primitively segmented Ryuthela spiders

Here, we provide a taxonomic revision of the liphistiid genus Ryuthela Haupt, 1983, endemic to Ryukyu archipelago, Japan, through a combination of molecular and morphological data in a phylogenetic framework. We barcoded 173 originally collected specimens of 15 putative species using the universal cytochrome c oxidase subunit I (COI) mitochondrial marker and used these data for species delimitation estimates. We find that Ryuthela consists of the five currently deemed valid species plus one named and as many as nine newly discovered species. Our findings shed light on species diversity of endemic spiders in one of the Asian biodiversity hotspots, and a formal taxonomy of 15 species completes the genus revision.