Diagnosis of the ‘ Grosphus ’ group

The three buthid genera Grosphus Simon, 1880, Neogrosphus Lourenço, 1995, and Teruelius gen. n. comprise a distinct assemblage of Madagascar buthids (= ‘ Grosphus ’ group) sharing the following set of characters:

Carapace subrectangular, weakly trapezoidal or nearly parallel-sided, surface densely granular, carinae indistinct except for superciliary carinae; frontal region of carapace flat, not sloped towards anterior margin; median eyes large, median ocular tubercle prominent, located forward of the carapace centroid (Figs. 165–180); 5 pairs of lateral eyes (3 large, 2 small) (Figs. 227–230); chelicerae with typical buthid dentition on fixed and movable fingers (Vachon, 1963), two enlarged denticles on ventral surface of fixed finger (Figs. 231– 238); sternum type 1, subtriangular; tergites granular, tergites I–VI with single, weak median carina, tergite VII with weak median carina and 2 pairs of strong lateral carinae; metasoma moderately elongate, segments I–III with 8–10 carinae, IV with 8 carinae, V with 3–5 carinae; telson vesicle bulbous, ovoid or elongate, with or without subaculear tubercle (Figs. 181–195); pectines with fulcra, 13–41 teeth, female with basal pectinal tooth dilated or elongated, lacking peg sensillae (Figs. 40–51, 196–210); hemispermatophore flagellum thicker at base, narrowed proximally, thickened distally (Figs. 52, 58, 60, 67, 71, 75, 78, 84); pedipalp chela elongate, smooth, carinae obsolete, surface typically with numerous short macrosetae (Figs. 21–24); finger dentition composed of 8–15 discrete linear rows of granules or denticles, each slightly oblique with proximal ends directed externally; rows either non-overlapping or slightly imbricated, proximal 3 granules in each row enlarged, 2 of these slightly displaced outwards as ‘external accessory’ granules; series of large, dentate internal accessory granules present, offset from main rows; both chela fingers with enlarged apical teeth, 3–4 external subdistal granules; pedipalps sexually dimorphic, dentate margins of fingers weakly or strongly scalloped proximally in males, straight in females, manus of males broader than that of females; trichobothrial pattern orthobothriotaxic, type A (Vachon, 1974), with femur d 1 - d 3 - d 4 in α-configuration (Vachon, 1975), patella d 3 external to dorsomedian carina (Fet et al., 2005); patella em much closer to est and et, than to esb 1 and esb 2, with em -est -et usually forming a compact triad (Figs. 345, 481a); chela manus with Eb 1 - Eb 2 angled distally, Eb 1 - Eb 2 - Eb 3 acute angle opening in proximal direction (γ-configuration) (Figs. 342, 478a); chela with db in proximal half to middle of fixed finger; legs III–IV with tibial spurs (Figs. 211–226, 261–262, 318–319, 364–365, 414–417, 487–488, 514–515, 540–541, 578–579, 618–619), tarsi without bristle-combs.

REMARKS. In describing the first ‘ Grosphus ’ group species, Scorpio (Androctonus) madagascariensis, Gervais (1844: pl. XI, fig. 3) illustrated the carapace showing forward placement of the median eyes, and also accurately depicted five pairs of lateral eyes, now recognized to be the prevalent buthid configuration (Loria & Prendini, 2014; Yang et al., 2013). In spite of this, Fage (1929) incorrectly declared that Grosphus (sensu lato) only bore 3 pairs of lateral eyes, and Lourenço (1996b) cited only 3–4 pairs. Moreover, only 3 pairs were described for: Grosphus ambre, G. darainensis, G. garciai, G. goudoti, G. halleuxi, G. hirtus, G. madagascariensis, G. makay, G. mandena, G. mayottensis, G. polskyi, G. rossii, G. simoni, G. rakotoariveloi, G. tavaratra, G. voahangyae, Teruelius ankarana, T. ankarafantsika, T. bemaraha, T. bicolor, T. bistriatus, T. eliseanneae, T. feti, T. ganzhorni, T. intertidalis, T. limbatus, T. magalieae, T. mahafaliensis, T. olgae, T. sabineae, T. waeberi (Lourenço, 1996b, 1999, 2001b, 2003c, 2005, 2012c, 2013b, 2014; Lourenço & Goodman, 2006, 2009; Lourenço & Wilmé, 2015a, 2015b, 2016; Lourenço et al., 2004, 2007a, 2009b, 2016c, 2017, 2018b). We confirm here that 5 pairs are indeed present in all species that we have examined: G. garciai (= G. hirtus), G. goudoti, G. ‘ halleuxi ’, G. hirtus, G. sp. nr hirtus, G. madagascariensis, G. ‘ mandena ’, G. voahangyae, Neogrosphus griveaudi, Teruelius ankarafantsika, T. ankarana, T. annulatus, T. bistriatus, T. feti, T. flavopiceus, T. grandidieri, T. intertidalis, T. limbatus, T. mahafaliensis and T. olgae (e.g., Figs. 227–230). We found only a few individual deviations from the standard pattern, such as 2 large and 2 small ocelli, that we regarded as developmental anomalies. We predict that other ‘ Grosphus ’ group species will also comply with the 5-eye pattern. Although undercounting of lateral eyes is perhaps attributable to overlooking of the smaller posterior and upper ocelli, 10 of the published 3-eye counts post-date introduction of the 5-eye model by Yang et al. (2013, coauthor Lourenço) and Loria & Prendini (2014). Paradoxically, Lourenço et al. (2007a) claimed 3 lateral eyes in boilerplate descriptions of G. hirtus and G. polskyi, yet their figures clearly depict all 5 lateral eyes as being present in both species. Vachon (1969) correctly reported 5 “nettement visibles” lateral eyes, 3 large and 2 small, in both sexes of Neogrosphus griveaudi . Although 3 pairs were described for N. blanci and N. andrafiabe (Lourenço, 1996b; Lourenço et al., 2015), we are skeptical that these counts are accurate.