Thorn Harvestmen

Acuclavella is a genus of thorn harvestmen in the family Ischyropsalididae, found in the Pacific Northwest. There are about seven described species in Acuclavella.

Acuclavella was formerly a member of the family Ceratolasmatidae, but was moved to Ischyropsalididae, along with Ceratolasmatidae which became the subfamily Ceratolasmatinae.

Acuclavella leonardi

The simple, distally tapering penis (Appendix VIII, Figure I) and short ovipositor (Appendix III, Figure 2) morphologies are conserved across species, with intraspecific variation seemingly as great as interspecific variation. Penis sheath with two sclerotized bands. Metatarsus of leg II with or without false leg articulations (Appendix IX). Distitarsi with three segments on legs I and II; distal end of legs III and IV with two constrictions, each comprised of two segments. All males with raised, glandular (Shear 1986), setose mound dorsally on basal article of chelicerae, setae often capped with secretions (MorphBank image 822802); mounds lacking in females. Chela teeth diaphanous, with two heavily sclerotized teeth distally on fingers (MorphBank image 822817). All leg coxae with prolateral and retrolateral tubercles in the form of distended clusters of warts (MorphBank image 828524). Epistome of stomotheca horn-like, projecting outward (MorphBank image 828520) to strongly decurved (MorphBank image 82215), without apparent interspecific trends. Pseudotrachea of pedipalpal coxaphysis sclerotized ctenoid (MorphBank image 822815).