The schizomid family Protoschizomidae, endemic to North America, is represented by two genera and 15 species. While most of the species are distributed in caves in the Sierra Madre Oriental system in Mexico; other species are found in caves in the Sierra Madre Occidental system. Recently, a new species of this family was described from a cave in the Mexican Trans-Volcanic Belt, representing the linking bridge between both Sierras. In the present contribution, we propose a new nomenclature of the pedipalp setae of the protoschizomids. We revise the phylogenetic status of Protoschizomidae using 137 morphological characters (including the proposed pedipalp setae) and 7 outgroup taxa using parsimony criteria. Based on our results, Protoschizomidae was recovered as monophyletic, but the monophyly of Protoschizomus Rowland, 1975 was not recovered because of the inclusion of Agastoschizomus Rowland, 1971 and the fossil Onychothelphynous bonneri Pierce, 1951. Therefore, we transfer the genus Onychothelyphonus Pierce, 1951 and species O. bonneri to this family, but other taxonomical changes were not considered.