Systematic Revision of the Troglomorphic North American Scorpion Family Typhlochactidae (Scorpiones: Chactoidea)

Abstract

The scorpion family Typhlochactidae Mitchell, 1971, endemic to eastern Mexico, comprises nine troglomorphic species specialized for life in hypogean and endogean habitats. Due to their cryptic ecology, inaccessible habitat, and apparently low population density, Typhlochactidae are poorly known. Only 29 specimens have been collected in 40 years. Four species are known from a single specimen, two species are known only from the male and three only from the female. We provide an illustrated revision of the family based on a reexamination of most specimens in the world's collections, including new specimens collected after the original descriptions and older specimens not previously described. Based on results of a recent cladistic analysis, Typhlochactidae are elevated, for the first time, from their former rank as subfamily, first of Chactidae and, more recently, of Superstitioniidae. Alacraninae, new subfamily is created to accommodate Alacran Francke, 1982. Stygochactas, new genus, is created to accommodate Typhlochactas granulosus Sissom and Cokendolpher, 1998 in a new combination. Sotanochactas Francke, 1986, Stygochactas andTyphlochactas Mitchell, 1971 are retained in subfamily Typhlochactinae . Diagnoses of the family and subfamilies are presented, followed by a key to the genera and species, revised diagnoses of the genera, revised diagnoses and descriptions, tabulated meristic data, and distribution maps of the species. Descriptions and diagnoses are illustrated with ultraviolet fluorescence and visible light photographs, providing a visual atlas to the morphology of these remarkable scorpions. A review of their taxonomic history is provided, the importance of trichobothriotaxy for their systematics discussed, and several misconceptions in the literature clarified.

Cheliceral Morphology in Solifugae (Arachnida): Primary Homology, Terminology, and Character Survey

“…Maury, 1980), the terms "width" (e.g., Brookhart and Muma, 1981;Vázquez and Gaviño-Rojas, 2000;Peretti and Willemart, 2007;Catenazzi et al, 2009) and "breadth" (Cloudsley-Thompson, 1961) are traditionally used to describe the vertical axis of the chelicera in the solifuge literature. In the present contribution, following Botero-Trujillo (2014) and in accordance with common usage in other groups (e.g., scorpion pedipalp chela, Vignoli and Prendini, 2009;Lourenço et al, 2012; crustacean cheliped propodus, Gregati and Negreiros-Fransozo, 2007) this is substituted with "height," whereas width (breadth) is reserved for the horizontal axis measured in dorsal view (Fig. 5).…”

SYSTEMATIC REVISION OF THE NEOTROPICAL SCORPION GENUSCHACTOPSISKRAEPELIN, 1912 (CHACTOIDEA: CHACTIDAE), WITH DESCRIPTIONS OF TWO NEW GENERA AND FOUR NEW SPECIES

“…7). However, the assumption of trichobothrial ''migration,'' invoked to account for such positional differences between putatively homologous trichobothria, has been repeatedly questioned (Lamoral, 1979;Francke and Soleglad, 1981;Francke, 1982;Stockwell, 1989;Sissom, 1990;Prendini, 2000;Prendini and Wheeler, 2005;Prendini et al, 2006;Francke and Prendini, 2008;Vignoli and Prendini, 2009;Prendini et al, 2010). There is neither evidence nor a plausible explanation for migration, accounting for movement of the trichobothria and their associated bipolar neurons, whereas there is abundant evidence for the loss or gain of trichobothria.…”

On the Troglomorphic Scorpion Troglotayosicus humiculum (Scorpiones, Troglotayosicidae), with First Description of the Adults

“…7B, D, F (dm): 15 on manus, four ventral (V 1 -V 4 ), ten external (Et 1 -Et 5 , Est, Esb, Eb 1 -Eb 3 ), one dorsal (Db); 11 on fixed finger, four external (et, est, esb, eb), five dorsal (dt, dst, dm, dsb, db), two internal (it, ib). The petite condition of Et 4 in Troglotayosicus is recognized here for the first time and results in a trichobothrial interpretation with greater similarity to typhlochactid species (all of which also exhibit petite Et 4 and Et 5 ; Vignoli and Prendini, 2009) than that presented by Botero-Trujillo and Francke (2009); see Prendini et al (2010) for trichobothrial notation in T. humiculum defined strictly on positional homology (the ''placeholder approach'').…”

“…Trichobothrial notation follows Vachon (1974), but we adopt a reinterpretation of Typhlochactas trichobothrial patterns proposed by Prendini and Wheeler (2005) and Vignoli and Prendini (2009). Furthermore, the trichobothrial notation used in this contribution does not necessarily imply homology with other species (i.e., trichobothria with the same designation in other species are not necessarily considered homologous); see Prendini et al (2010) for trichobothrial notation in T. humiculum defined strictly on the basis of positional homology (the ''placeholder approach'').…”

“…In response, Fet and Soleglad (2005) reinstated their previous classification (Soleglad and Fet, 2003), but it was not universally accepted. Lourenço (2006), for example, suggested that Troglotayosicus should be retained in Troglotayosicidae or considered incertae sedis in Chactoidea, while Volschenk and Prendini (2008), Botero-Trujillo and Francke (2009), Vignoli and Prendini (2009) and Prendini et al (2010) also recognized Troglotayosicidae. Prendini et al (2010) confirmed the monophyly of Troglotayosicus, but its phylogenetic relationships with other chactoid families remain to be rigorously tested.…”