Trypanothacus buettikeri ( Hendrixson, 2006 ) Lowe & Kovařík & Stockmann & Šťáhlavský, 2019

Lowe, Graeme, Kovařík, František, Stockmann, Mark & Šťáhlavský, František, 2019, Trypanothacus gen. n., a new genus of burrowing scorpion from the Arabian Peninsula (Scorpiones: Buthidae), Euscorpius 277, pp. 1-30 : 22

Trypanothacus buettikeri ( Hendrixson, 2006) , comb. n.

( Figs. 90–108 )

Buthacus buettikeri Hendrixson, 2006: 47–52 , figs. 4–5, plates 3–4 (in part); Lourenço & Qi, 2006: 161; El-Hennawy, 2009: 121, 126; Lourenço & Leguin, 2009: 104, 107, tab. 1; Desouky & Alshammari, 2011: 195–196, figs. 6–7 (?) (in part); Kovařík et al., 2013: 3; El-Hennawy, 2014: 45; Kovařík et al., 2016b: 2; Kovařík, 2018: 7.

TYPE LOCALITY AND TYPE DEPOSITORY. Saudi Arabia, Um ad- Dabah, NHMB.

TYPE MATERIAL EXAMINED. Saudi Arabia: 1♂ (holotype), Um ad-Dabah [23°54'N 45°01'E, 920 m a.s.l.], 13. V.1980, leg. W. Büttiker, NHMB 0587 (=172a); 1♀ (paratype), Khashm Dhibi [23°50'N 45°05'E, 750 m a.s.l.], 10.X.1981, leg. W. Büttiker, NHMB 0896 (=172e); 3♀ 1 juv. (paratypes), Kushm Dibi [24°14'N 46°05'E, 850 m a.s.l.], 30.I.1981, leg. W. Büttiker, NHMB 172cd .

OTHER MATERIAL EXAMINED. 1♂ (fragmented), Wadi Turabah [25°30'N 41°17'E, 1,430 m a.s.l.], XII.1986, leg. W. Büttiker, NHMB Sc509 .

DISTRIBUTION. SAUDI ARABIA. Central plateau, Najd desert; east of Harrat Khaybar lava field, east of Hijaz mountains.

DIAGNOSIS. A member of Trypanothacus gen. n. differentiated from its congener as follows: pedipalp femur L/W ♂ 2.5, ♀ 2.2; pedipalp patella L/W ♂ 2.1–2.2, ♀ 2.3, chela L/W ♂ 3.2–3.6, ♀ 4.0; metasoma IV L/D ♂ 1.8–2.0, ♀ 1.9, V L/D ♂ 2.4–2.6, ♀ 2.4.

COMMENTS. Hendrixson originally described Buthacus buettikeri on the basis of a series of specimens from several localities in Saudi Arabia (Hendrixon, 2006: 47, 51). We examined part of the type series and concluded that the holotype male (No. 172a; Figs. 43 , 90–91 , 94–101 ) and paratype females from Khashm Dhibi (Nos. 172cd, NHMB 0896=172e; Figs. 44 , 92–93 , 103–106 ), from the Najd plateau region of central Saudi Arabia, belong to Trypanothacus gen. n.. However, several other specimens of the type series from widely disjunct sites along the western slopes of the Asir ranges (facing the Red Sea Coast), differed from the holotype and are associated with the Buthacus leptochelys (Ehrenberg, 1829) species complex of the genus Buthacus (i.e., female paratypes including NHMB 515=172b, 630=172f and 620= 172g; from Jabal al-Ghamdiyah, Wadi Maraum, Addar, Kijat (examined); also likely including MNHN RS8425 from Makkah By-pass, based on specimen photographs on the MNHN website). In light of these misidentifications, the status of other MNHN paratypes from a widely disjunct site near the northern border of Saudi Arabia (ca. 1,030 km from the type locality) remains unclear.

Desouky & Alshammari (2011) recorded B. buettikeri from the Ha’il region in the central plateau of Saudi Arabia (Hufair, Sarraa near Al-Ghazala), on “sandy desertˮ. In photographs, their adult female (carapace L 5.92 mm) (fig. 7) appears morphometrically consistent (e.g. patella L/W 2.57, metasoma I L/W 1.02) with females of the type series that we have examined, however their adult male (carapace L 6.4 mm) (fig. 6) has markedly different morphometrics with much more slender pedipalps and metasoma (e.g. pedipalp patella L/W 2.95, metasoma I L/W 1.38) than in the male types of B. buettikeri . It is also more slender than all males of T. barnesi sp. n. in our type series. This would seem to indicate large variation in male morphometrics of B. buettikeri , maybe reflecting local geographic races as Ha’il is located some distance northwest of the type locality. However, a large adult male that we determined as T. buettikeri , has morphometrics more robust than the holotype, yet was collected from Wadi Turabah, relatively closer to the Ha’il region. As we have not studied Ha’il region material, we withhold judgement on the taxonomic status of those populations, but the large morphometric difference likely indicates a different species. Desouky & Alshammari (2011: 196) assumed B. williamsi Lourenço & Leguin, 2009 , to be a junior synonym of B. buettikeri , but did not justify this by comparative study of the types of either species. They also claimed that the telson and aculeus in B. buettikeri was “clearly more slender and elongated” than in B. leptochelys , misrepresenting Hendrixson (2006), when the opposite is true.

AFFINITIES. See comments under T. barnesi sp. n.

Figures

Figures 90–93: Trypanothacus buettikeri comb. n. Figures 90–91. Male holotype in dorsal (90) and ventral (91) views. Figures 92–93: Female paratype in dorsal (92) and ventral (93) views. Scale bars: 10 mm.

Figures 94–95: Trypanothacus buettikeri comb. n. Male holotype, carapace and tergites I–IV (94), coxosternal area and sternites I–II (95). UV fluorescence. Scale bar: 2 mm.

Figures 96–106: Trypanothacus buettikeri comb. n. Figures 96–101. Male holotype, lateral view of metasoma and telson (96), dorsal views of pedipalp chela (97) patella (98) and femur (99), external views of pedipalp chela (100) and patella (101). Figure 102. Male from Wadi Turabah (NHMB No. 509), dorsal view of pedipalp patella. Figures 103–106. Female paratype (NHMB 896), lateral views of metasoma (103) and pedipalp chela (104), dorsal view ofpedipalp patella (105) and femur (106).UV fluorescence.Scale bars:2 mm (96), 2 mm (97–101), 2 mm (102), 2 mm (103), 2 mm (104–106).

Figures 107–110: Morphometric scaling relations of the telson of fossorial ‘Buthus group’ scorpions. Figure 107. Double logarithmic scatterplot of telson vesicle length/ depth (L/ D) ratio vs. aculeus length normalized to vesicle length (aculeus L/ vesicle L), for large pelophiles/ semipsammophiles (4 genera, 53 species) (Buthus, Odontobuthus, Pantobuthus: orange circles; Trypanothacus gen. n.: blue circles) and large psammophiles/ ultrapsammophiles (6 genera, 29 species) (Buthacus: cyan circles; Vachoniolus: dark green circles; Apistobuthus, Buthiscus, Liobuthus, and Plesiobuthus: yellow circles). Dark line: linear least squares regression fit to all data shown (Pearson correlation coefficient, R = 0.57). Upper right inset: diagram of measurements estimated from inverted telson lateral profiles, with dorsal surface of vesicle approximately leveled; SA = ventral profile length of aculeus from base point to tip, LV = length of vesicle from anterior limit or inflection point to aculeus base point; HV = vesicle depth or height (distance between dorsal and ventral tangent planes). Base point was placed at local minimum of inverted ventral profile curve. SA was calculated by cubic spline fit (>10 anchor points). For a minority of broken tips, SA was estimated by intersecting extrapolated dorsal and ventral profile curves (<5%). Figure 108. Scatterplot of fossorial buthids in Figure 107, superposed upon larger scale plot of Order Scorpiones (gray circles). Gray line: linear least squares regression fit to Order Scorpiones data (including data in Figure 107) (Pearson correlation coefficient, R = –0.62).Also plotted are data from small ‘Buthus group’ psammophiles/ ultrapsammophiles (5 genera, 10 species: Compsobuthus arabicus, Lanzatus somalilandus, Neobuthus kutcheri, Picobuthus dundoni, P. wahibaensis, Anomalobuthus krivochatskyi, A. pavlovskyi, A. rickmersi, A. lowei, A. talebii) (dark yellow circles). Figure 109. Double logarithmic scatterplot of carapace length (L) vs. aculeus length normalized to vesicle length (i.e., aculeus L/ vesicle L) for psammophile/ ultrapsammophile members of the ‘Buthus group’, including large species in Figure 107, and small species in Figure 108 (dark yellow circles). Blue line: linear least squares regression fit to all data shown (Pearson correlation coefficient, R = 0.74). Figure 110. Scatterplot of psammophile buthid data in Figure 109 (all in one color, blue circles) superposed upon larger scale plot of Order Scorpiones (gray circles). Gray line: linear least squares regression to Order Scorpiones data (including data in Figure 109) (Pearson correlation coefficient, R = –0.01). Also plotted are data from bothriurid genus Brachistosternus (43 species) (magenta triangles), and corresponding linear least squares regression fit (R = 0.39). All plots in Figures 107-110 include data from both males and females. Data were assembled by mining taxonomic literature or directly measuring specimens. Included are 1854 species or subspecies (1331 ♂, 1201 ♀) representing all known extant genera (1841 species or subspecies) plus 7 fossil genera (13 species).

Figures 29–46: Figures 29–42: Trypanothacus barnesi gen. et sp. n. Figures 29–40. Pedipalp segments. Figures 29–38. Male holotype, chela dorsal (29), external (30), and ventral (31) views. Patella dorsal (32), external (33) and ventral (34) views. Femur and trochanter internal (35), dorsal (36), and ventral (37) views. Movable finger dentition (38). Trichobothrial pattern is indicated in Figures 30–33 and 35–36. Figures 39– 40. Female paratype from the type locality, chela dorsal (39) and external (40) views. Figures 41–42. Telson, male holotype (41) and female paratype from type locality (42), lateral views. Figures 43–44: T. buettikeri comb. n., pedipalp chela dorsal, male holotype (43) and female paratype (44). Figures 45–46: Buthacus stockmanni Kovařík et al., 2016, telson, male holotype (45) and female paratype (46), lateral views.