Genus Butheolus Simon, 1882

Butheolus Simon, 1882: 248 .

Butheolus: Karsch, 1886: 76; Pocock, 1890: 121–122 (part); Pocock, 1892: 47; Laurie, 1896: 131; Lönnberg, 1897 b; 194 (part); Kraepelin, 1899: 34 (part); Pocock, 1900: 28 (part); Kraepelin, 1905: 337, 353; Simon, 1910: 77; Hirst, 1911: 462, 464; Birula, 1917a: 164; Birula, 1917b: 55; Werner, 1934:145, 266, 270, 294, 299; Kästner, 1941: 231; Sreenivasa- Reddy, 1970: 18; Stahnke, 1972: 127, 129, fig. 12 (part); Vachon, 1974: 906; Vachon, 1975: 1598 (part); Vachon, 1980: 253 (part); Francke, 1985: 6, 15; Vachon & Kinzelbach, 1987: 92 (part); Sissom, 1990: 97, 101 (part); El-Hennawy, 1992: 97, 101, 104, 114 (part); Nenilin & Fet, 1992: 17; Lourenço & Vachon, 1995: 297; Kovařík, 1996: 177–178; Kovařík, 1998a: 117; Kovařík, 1998b: 105 (part); Fet & Lowe, 2000: 88 (part); Lourenço, 2001: 179; Kovařík, 2003: 137–138 (part); Soleglad & Fet, 2003: 88; Kovařík, 2004: 2–3, 25 (part); Fet & Soleglad, 2005: 11; Fet, Soleglad & Lowe, 2005: 3, 11, 22, fig. 23 (part); Lourenço, 2005: 26–28; Prendini & Wheeler, 2005: 481; Hendrixson, 2006: 56 (part); Lourenço & Qi, 2006: 91–93 (part); Dupré, 2007: 4, 12, 17 (part); Kovařík, 2009: 23, 31; Hennawy, 2009: 126 (part); Lowe, 2010a: 37, 44; Lourenço & Leguin, 2011: 1; Kovařík & Lowe, 2012: 1–2, 18–23 (part); Kovařík et al., 2013: 4; Yang et al., 2013: 5; Loria & Prendini, 2014: 25, tab. 5; Lowe et al., 2014: 120, fig. 98; Lowe & Kovařík, 2016: 1, 43; Loria & Prendini, 2018: tab. 1.

TYPE SPECIES. Butheolus thalassinus Simon, 1882, by subsequent designation (Kraepelin, 1895: 5; Pocock, 1895: 295).

Simon (1882) described B. thalassinus as a new species under Butheolus, but did not explicitly designate it as the type species. In the appendix to the same publication, he described a second new species under the same genus ( B. aristidis), leaving ambiguity about which was the type species. Later, Birula (1898: 292) transferred B. aristidis to Orthochirus . According to Fet & Lowe (2000: 88), B. thalassinus was established as the type species of Butheolus by subsequent designation of Simon (1910: 77). However, a subsequent designation according to ICZN Art 69.1.1 had already been made earlier by Kraepelin (1895: 5) and Pocock (1985: 295) when they referenced B. thalassinus as the type species of Butheolus, and it was also cited as the type species by Pocock (1900: 28).

DIAGNOSIS. Small buthids (Kovařík, 2009; Sissom, 1990), adults 24–36 mm in length; carapace strongly trapezoidal, ratio of posterior W/ anterior W 1.9 –2.5, preocular area inclined downwards towards anterior margin, surface densely granular, without distinct carinae; tergites densely granular, tergites I–III lacking carinae or with weak median carina, IV–VI weakly tricarinate with median and paired lateral carinae; tergite VII with broad median carina, two pairs of lateral carinae; posterior margins of sternites III–VI armed with fringe of non-contiguous digitate denticles that are larger in males; metasomal segments nearly uniform in width and depth, robust with granulated carinae, segments II–V densely granular on lateral and ventral intercarinal surfaces; metasoma I–III with 10 carinae, IV with 4 or 6 complete carinae (ventrosubmedian, ventrolateral pairs complete, dorsosubmedian pairs may be complete, dorsolateral pairs weak or incomplete), V with 2 complete carinae (ventrolateral pairs); ventrolateral carinae on metasoma V without enlarged lobate dentition; telson with slightly elongated ovoid vesicle, with or without a blunt subaculear tubercle, aculeus shorter than vesicle; pectines with fulcra; hemispermatophore with flagellum separated from a 3-lobed sperm hemiduct, basal lobe a small, narrow, hook-like process; chelicerae with characteristic buthid pattern of dentition (Vachon, 1963), two denticles on ventral aspect of fixed finger; pedipalps orthobothriotaxic, type Aβ (Vachon, 1974, 1975), patella with d 3 internal to dorsomedian carina, chela manus with V 2 not strongly displaced internally, V 1 – V 2 axis nearly collinear with long axis of chela, chela fixed finger with db on proximal half of finger between esb and est, it near tip; pedipalps short, chelae small with carinae reduced or obsolete, dentate margins of fingers armed with 6–7 (rarely 8) non-imbricated linear subrows of primary denticles; subrows flanked by mid-row internal and proximal external accessory denticles; movable finger with 3 enlarged subdistal denticles; males without recess or scalloping of dentate margins at base of pedipalp fingers, with chela manus narrower than females; tergites lacking macrosetae; tibial spurs present on legs III–IV; basitarsi I–III with regular series of long macrosetae on retrosuperior, retroinferior and inferior margins; ventral surfaces of telotarsi with paired rows of macrosetae; prolateral and retrolateral tarsal spurs present on all legs; moderate sexual dimorphism in setation, macrosetae on carapace, pedipalps, legs, sternites and metasoma longer in females than males.

REMARKS. Sexual dimorphism in setation is apparent in Butheolus, but is not as pronounced as it is in Neobuthus Hirst, 1911, in which males usually bear much shorter, stouter macrosetae than females (Kovařík & Lowe, 2012).