The identities of Pinnotheres villosulus Guérin-Méneville, 1832, P. edwardsi De Man, 1887, and P. trichopus Tesch, 1918, with description of a new Indo-West Pacific genus of pinnotherid crab (Decapoda: Brachyura: Pinnotheridae)

Abstract Nepinnotheres villosulus (Guérin-Méneville, 1832) [Guérin-Méneville, 1829–1837] [type locality: Timor] and Nepinnotheres edwardsi (De Man, 1887) [type locality: Mergui Archipelago], as currently understood, are both reportedly widespread in Southeast Asia and northern Australia, and unique in the genus in having females densely covered by a setal tomentum that completely obscures the surfaces of the carapace and pereiopods. Based on the limited information contained in the type accounts, N. edwardsi and N. villosulus appear indistinguishable, but this cannot currently be confirmed by comparing type material because the holotype of N. villosulus, the senior name, is lost. A neotype is therefore designated for N. villosulus to fix its identity and taxonomic status as a senior synonym of N. edwardsi. In addition to the unique setation pattern of female N. villosulus, males of the species also present important differences from those of male Nepinnotheres sensu stricto. Pinnotheres trichopusTesch, 1918 [type locality: Elat, Great Kei Island, Indonesia], is also shown to be a junior synonym of P. villosulus. Moreover, recent molecular phylogenetic analyses determined that N. villosulus is phylogenetically distant from Nepinnotheres sensu stricto. As such, we establish a new genus for N. villosulus.