Thorellius Soleglad and Fet, 2008

González-Santillán, Edmundo & Prendini, Lorenzo, 2018, Systematic Revision Of The North American Syntropine Vaejovid Scorpion Genera Balsateres, Kuarapu, And Thorellius, With Descriptions Of Three New Species, Bulletin of the American Museum of Natural History 2018 (420), pp. 1-1 : 25-26

Thorellius Soleglad and Fet, 2008

Figures 5 –15, table 8

Vejovis intrepidus Thorell, 1876 [= Thorellius intrepidus (Thorell, 1876) ], type species, by original designation.

Vejovis second section (part): Hoffmann, 1931: 373.

Vaejovis second section (part): Francke and González-Santillán, 2007: 590.

Vaejovis intrepidus group (part): Sissom, 1989: 180; 1991a: 24, 26; 1991b: 24, 26; 1993: 68; Stockwell, 1992: 408, 409; Lourenço and Sissom, 2000: 135; Sissom, 2000: 537, 551; Armas and Martín-Frías, 2001: 8; Hendrixson, 2001: 47; González-Santillán, 2004: 30, 31; Ponce-Saavedra and Sissom, 2004: 539, 541; Graham and Fet, 2006: 7; Soleglad and Fet, 2008: 1, 95, 102; McWest, 2009: 66, 69, 70, 100–102, table 1; Santibáñez-López and Sissom, 2010: 52; Miranda-López et

al., 2012: 966; González-Santillán and Prendini, 2013: 7, 9, 11, 14, 24, 44, 55,

table 3; 2016: 8.

Vaejovis punctipalpi group (part): Fet et al., 2006: 9, table 1; Soleglad and Fet, 2006: 6.

Thorellius (part): Soleglad and Fet, 2008: 1, 95, 102; Baldazo-Monsivaiz et al., 2012: 144; 2013: 100, 101, table 1

Thorellius: González-Santillán and Prendini, 2013: 3 , 6, 7, 16, 17, 18, 21, 24, 30, 35, 38, 39, 43, 44, 51–53, 55, 56, 59, figs. 1E, 5, 17, 20, 21, tables 1, 3; Ponce-Saavedra and Francke, 2013: 77, table 2; Quijano-Ravel and Ponce Saavedra, 2014: 17, 18, 20, table 2; Loria and Prendini, 2014: 26, table 5; Ayrey and Soleglad, 2015: 5; Santibáñez-López et al, 2015: 7; González- Santillán and Prendini, 2016: 8, 36;

Dupré, 2017: 14.

DIAGNOSIS: Thorellius may be separated from other genera of Syntropinae by the presence of nine retrolateral ventral major macrosetae on the basitarsus of leg III (fig. 11C–G). Most other syn- tropine genera bear six or seven retrolateral ventral major or minor macrosetae, whereas Syntropis bears more than 10. The dorsal surface of the pedipalp femur is finely and sparsely granular in all species of Thorellius , whereas in other syntropine genera the dorsal surface is smooth, matte, or granular. The pedipalp patellar retrolateral dorsosubmedian and retrolateral median carinae are smooth and weakly developed in most species of Thorellius , except T. wixarika , sp. nov., in which the carinae are granular, whereas in other syntropine genera these carinae are absent or granular, as in Kochius .

Thorellius is most closely related to Balsateres , with which it shares broad pedipalpal and metasomal carinae, but the carinae are moderately to densely granular in Thorellius , instead of smooth, as in Balsateres . A distinct proximal gap between the pedipalp chela fingers, when closed, is evident in both sexes of Thorellius , unlike Balsateres , in which the fingers are sublinear, without a distinct proximal gap. The two genera also differ in base coloration and infuscation. Thorellius are dark and reddish in color, with infuscation on the carapace and tergites, whereas Balsateres is yellow and almost immaculate, except for the ocular tubercle, which is infuscate. Thorellius intrepidus shares with Balsateres a pair of prolateral denticles at the seventh position on the pedipalp chela movable finger, whereas other species of Thorellius possess a single denticle at the seventh position. However, T. intrepidus may be separated from Balsateres by the densely granular carinae and intercarinal surfaces, which are smooth in Balsateres .

Species of Thorellius superficially resemble Kochius , in which the pedipalp chelae are relatively incrassate. However, Thorellius may be distinguished by the broad, raised pedipalp carinae, comprising clustered granules, unlike Kochius , in which the carinal granulation is moniliform. The two genera also differ in the macrosculpture of the ventral submedian carinae of metasomal segments I–III, which are costate to weakly denticulate in Thorellius but granular in Kochius .

Thorellius contains the largest and most robust scorpions in subfamily Syntropinae . The holotype of T. intrepidus is 94 mm in length ( Sissom, 2000). Syntropis , the only genus with adults similar in total length, is comparatively slender, with narrow, elongated pedipalps, legs, and metasoma.

INCLUDED SPECIES: Thorellius intrepidus (Thorell, 1876) ; T. cristimanus ( Pocock, 1898) ; T. tekuani , sp. nov.; T. wixarika , sp. nov.; and T. yuyuawi , sp. nov.

DISTRIBUTION: Thorellius is endemic to central-western Mexico and distributed from the interior to the Pacific coast. It has been recorded from the states of Aguascalientes, Colima, Estado de México, Guanajuato, Guerrero, Jalisco, Michoacán, and Nayarit, and probably also occurs in Sinaloa (figs. 1–3). Hoffmann’s (1931) records of T. intrepidus from Veracruz (Catemaco) on the eastern coast of Mexico are probably erroneous; extensive fieldwork has not yielded new collections from this area ( González-Santillán and Prendini, 2013) and the specimens were probably mislabeled.

ECOLOGY: Species of Thorellius inhabit subtropical deciduous forest from sea level to 1760 m and have been collected on the surface at night with UV light detection or by turning stones during the day. Thorellius species are active only during the rainy season and estivate during the dry season. Although González-Santillán (2004) suggested that T. intrepidus is pelophilous, the absence of fossorial adaptations suggests otherwise. The habitat and habitus of Thorellius are consistent with the lapidicolous ecomorphotype ( Prendini, 2001).

REMARKS: As redefined by González-Santillán and Prendini (2013), Thorellius accommodates a subset of species previously assigned to Hoffmann’s (1931) “second section” of Vaejovis , later termed the intrepidus group by Sissom (1989), for which Soleglad and Fet (2008) devised the name Thorellius , without quantitatively testing its monophyly or composition. As defined by Soleglad and Fet (2008), Thorellius was consistently poly- phyletic in the phylogenetic analyses presented by González-Santillán and Prendini (2013, 2015a), necessitating its relimitation and redefinition.

Figures

FIGURE 5. Balsateres González-Santillán and Prendini, 2013, Kuarapu Francke and Ponce-Saavedra, 2010, and Thorellius Soleglad and Fet, 2008, carapaces. A. Balsateres cisnerosi (Ponce-Saavedra and Sissom, 2004), ♂ (CNAN SC2441). B. Kuarapu purhepecha Francke and Ponce-Saavedra, 2010, paratype ♂ (AMNH). C. Thorellius cristimanus (Pocock, 1898), ♂ (AMNH). Scale bars = 1 mm