A new Indo-Malayan family of Grassatores (Arachnida, Opiliones, Laniatores)

Abstract

The laniatorean family Phalangodidae has been largely reduced to a core of Holarctic species, however many taxa were never formally transferred to other families. We examined a group of harvestmen related to Beloniscus Thorell, 1891, from Southeast Asia and determined the nature of the relationships of the "Beloniscus-like harvestmen", herein described as the new family Beloniscidae fam. nov., in the broad context of Laniatores. Based on a molecular phylogenetic analysis of a broad representative laniatorean Sanger-sequences dataset we found support for our taxonomic hypotheses that 1) inclusion of Beloniscidae fam. nov. in Phalangodidae would render the family non-monophyletic, and 2) Beloniscidae fam. nov. represent a lineage that is morphologically and genetically distinct from all other known laniatorean families. The new family Beloniscidae is endemic to SE Asia and comprises 37 species in two new subfamilies: Beloniscinae subfam. nov. and Buparinae subfam. nov. Beloniscinae includes the genera Beloniscellus Roewer, 1931, Beloniscops Roewer, 1949, Belonisculus Roewer, 1923, Beloniscus (type genus) and Kendengus Roewer, 1949. Buparinae includes the genera Buparellus Roewer, 1949, Bupares Thorell, 1889 (type genus), Buparomma Roewer, 1949. Members of Beloniscidae are relatively homogeneous in their external morphology, but are recognized by well-marked genitalic features. Male genitalia are described for exemplar species, and the morphology is compared to that of Epedanidae. Names are given to two new genitalic structures: sella curulis and pseudocalyx.