Three new species in the harvestmen genus Acuclavella (Opiliones, Dyspnoi, Ischyropsalidoidea), including description of male Acuclavella quattuor Shear 1986.

In Shear’s 1986 cladistic analysis of the Ischyropsalidoidea, he described the new genus Acuclavella including four new species from the Pacific Northwest states of Washington and Idaho. Several of these species descriptions were based on very limited sample sizes. Our recent field work has increased by more than an order of magnitude both the number of specimens and known localities for Acuclavella. We use this new material to interpret species limits in Acuclavella using morphometric analyses and DNA sequence data from four gene regions. We sequence for the first time the protein-coding homolog of the WNT2 gene for phylogenetic reconstruction in Opiliones. Our multi-locus phylogeny corroborates a sister relationship between Acuclavella and Ceratolasma, as hypothesized using morphology by Shear (1986). Within Acuclavella, morphometric clusters and reciprocal allelic monophyly allows recognition of three additional species: Acuclavella leonardi sp. n., A. sheari sp. n., and A. mak...