The genus Nuncia has long been the most speciose within the Opiliones family Triaenonychidae, comprising 63 species and subspecies distributed across New Zealand and South America. Recent molecular studies utilizing Sanger sequencing and ultraconserved elements (UCEs) have indicated that this genus is not monophyletic, and true Nuncia are actually confined to New Zealand. Here, the morphology of all South American triaenonychids is re-examined and DNA sequence data compiled from three markers (18S rRNA, 28S rRNA and cytochrome c oxidase subunit I) for a large number of triaenonychid species, including specimens from all areas with species currently and formerly classified in Nuncia to reassess their phylogenetic position. Based on our findings we 1) revalidate the genus Chilenuncia (Muñoz-Cuevas, 1971) nom. rest.; 2) describe five new genera: Fresiaxgen. nov., Mistraliagen. nov., Laftrachiagen. nov., Lautariagen. nov., Nerudiellagen. nov.; 3) redescribe five species: Fresiax spinulosacomb. nov., Mistralia verrucosacomb. nov., Chilenuncia chilensiscomb. nov., Chilenuncia rostratacomb. nov., Nerudiella americanacomb. nov.; and 4) describe 22 new species of South American triaenonychids: Fresiax conicasp. nov., Fresiax fraysp. nov., Fresiax mauryisp. nov., Fresiax pichicuysp. nov., Mistralia ramirezisp. nov., Laftrachia robinsp. nov., Lautaria ceacheisp. nov., Nerudiella cachaisp. nov., Nerudiella caramavidasp. nov., Nerudiella cautinsp. nov., Nerudiella choapasp. nov., Nerudiella curisp. nov., Nerudiella goroisp. nov., Nerudiella jaimeisp. nov., Nerudiella mallecosp. nov., Nerudiella pencosp. nov., Nerudiella pichisp. nov., Nerudiella portaisp. nov., Nerudiella quenessp. nov., Nerudiella vilchessp. nov., Nerudiella wekufesp. nov., and Nerudiella zapallarsp. nov. Furthermore, we provide detailed illustrations of all the South American species belonging to these lineages formerly classified in Nuncia.
