A Family Affair: Diagnosing and Delimiting Prostygnidae (Opiliones: Gonyleptoidea)

Abstract

The former subfamily Prostygninae was recently elevated to family rank, and its phylogenetic relationships were investigated based on molecular data. In this study, we provide a revised morphological diagnosis for the family, focusing on characters from the exomorphology and male genital morphology. Morphological data supporting their inclusion in the MECO clade are provided. Additionally, a key to the genera is presented, and Prostygnus stellatussp. nov., a new Ecuadorian species, is described. The geographic distribution of prostygnid species is mapped. An overview of the inclusion and exclusion of genera formerly within Prostygninae, but currently in Gonyleptoidea incertae sedis, is presented, and the following new familial assignments are proposed: Binamballeus Roewer, 1952 and Puna metatarsalis (Kury, 1994) comb. nov. (transferred to Cranaidae), Sclerostygnellus Roewer, 1943 (transferred to Manaosbiidae) and Globitarsus Roewer, 1913, Lisarea Roewer, 1943, Meridanatus Roewer, 1943, Micropachylus Roewer, 1913, Prostygnidius Roewer, 1915, and Troya Roewer, 1914 (all transferred to Nomoclastidae). Three subjective synonyms of Troya are proposed: Peladoius Roewer, 1914 syn. nov., Prostygnellus Roewer, 1914 syn. nov., and Minyssus Roewer, 1943 syn. nov., combining their species with Troya and, finally, Prostygnellus riveti Roewer, 1914 is considered as a junior secondary homonym of Troya riveti Roewer, 1914 syn. nov.