The short-tailed whipscorpion genus, Stenochrus Chamberlin, 1922 (Schizomida: Hubbardiidae Cook, 1899), occurring in North and Central America, is redefined and revised based on simultaneous phylogenetic analysis of 61 morphological characters and 2968 aligned DNA nucleotides from two markers in the nuclear genome, the internal transcribed spacer (ITS) and 28S rDNA, and two markers in the mitochondrial genome, cytochome c oxidase subunit I (COI) and 12S rDNA, for a comprehensive taxon sample.
Six new genera are described: Ambulantactus, gen. nov.; Baalrog, gen. nov.; Harveyus, gen. nov.; Nahual, gen. nov.; Schizophyxia, gen. nov.; Troglostenochrus, gen. nov. Heteroschizomus Rowland, 1973, stat. rev., is revalidated and its type species, Heteroschizomus goodnightorum Rowland, 1973, reinstated.
Six new species are described: Ambulantactus aquismon, sp. nov.; Ambulantactus montielae, sp. nov.; Baalrog yacato, sp. nov.; Harveyus contrerasi, sp. nov.; Heteroschizomus kekchi, sp. nov.; Nahual bokmai, sp. nov.
Eighteen new combinations are created by transferring species, previously accommodated in Stenochrus, to other genera: Ambulantactus davisi (Gertsch, 1940), comb. nov.; Baalrog magico (Monjaraz-Ruedas and Francke, 2018), comb. nov.; Baalrog sbordonii (Brignoli, 1973), comb. nov.; Harveyus mexicanus (Rowland, 1971a), comb. nov.; Harveyus mulaiki (Gertsch, 1940), comb. nov.; Harveyus reddelli (Rowland, 1971a), comb. nov.; Heteroschizomus meambar (Armas and Vi´quez, 2010), comb. nov.; Heteroschizomus orthoplax (Rowland, 1973a), comb. nov.; Heteroschizomus silvino (Rowland and Reddell, 1977), comb. nov.; Nahual caballero (Monjaraz-Ruedas and Francke, 2018), comb. nov.; Nahual lanceolatus (Rowland, 1975), comb. nov.; Nahual pallidus (Rowland, 1975), comb. nov.; Pacal moisii (Rowland, 1973), comb. nov.; Pacal tepezcuintle (Armas and Cruz-Lo´pez, 2009), comb. nov.; Schizophyxia bartolo (Rowland, 1973), comb. nov.; Schizophyxia lukensi (Rowland, 1973), comb. nov.; Troglostenochrus palaciosi (Reddell and Cokendolpher, 1986), comb. nov.; Troglostenochrus valdezi (Monjaraz-Ruedas, 2012), comb. nov.
The male of B. sbordonii is determined to be heterospecific with the holotype female and described as B. yacato. The females of H. goodnightorum and N. lanceolatus are described for the first time. Following these revisions, seven species remain within Stenochrus: Stenochrus alcalai Monjaraz-Ruedas and Francke, 2018; Stenochrus chimalapas Monjaraz-Ruedas and Francke, 2018; Stenochrus gruta Monjaraz-Ruedas and Francke, 2018; Stenochrus guatemalensis (Chamberlin, 1922); Stenochrus leon Armas, 1995; Stenochrus pecki (Rowland, 1973); Stenochrus portoricensis Chamberlin, 1922.
Olmecazomus, nom. nov., is proposed as a replacement name for the junior homonym, Olmeca Monjaraz-Ruedas and Francke, 2017, creating three new combinations: Olmecazomus brujo (Monjaraz-Ruedas and Francke, 2017), comb. nov.; Olmecazomus cruzlopezi (Monjaraz-Ruedas and Francke, 2017), comb. nov.; Olmecazomus santibanezi (Monjaraz-Ruedas and Francke, 2017), comb. nov.
A key to identification of the hubbardiid genera of North America is provided and the utility of various character systems for the diagnosis of schizomid genera discussed. The integration of morphological and molecular data not only increased knowledge of the schizomid diversity in the New World but disentangled what was once considered a homoplastic and variable morphology in a large "catch-all" genus into discrete units each diagnosable by unique character combinations.