Parabuthus setiventer, Prendini & Esposito, 2010

Prendini, Lorenzo & Esposito, Lauren A., 2010, A reanalysis of Parabuthus (Scorpiones: Buthidae) phylogeny with descriptions of two new Parabuthus species endemic to the Central Namib gravel plains, Namibia, Zoological Journal of the Linnean Society 159 (3), pp. 673-710 : 683-696

turnoff from Ganab road, 23°08′41.9″S, 15°31′24.4″E, 20.i.2009, L. Prendini, T.L. Bird & J. Huff, 1053 m, Central Namib gravel plains on north side of Tumasberg, Stipagrostis grassland with few granite outcrops, sandy-loam soil, UV detection on cool, dark night, light breeze, specimens sitting on gravel plains, sympatric with Parabuthus brevimanus , Uroplectes gracilior Hewitt, 1914 , and Opistophthamus jenseni (Lamoral, 1972) , 3 ♂ (AMNH); Ganab Station, 200 m east of Ganab road, 23°08′37.5″S, 15°31′17.2″E, 20.i.2009, L. Prendini, T.L. Bird & J. Huff, 1044 m, Central Namib gravel plains on north side of Tumasberg, Stipagrostis grassland with few granite outcrops, sandy-loam soil, UV detection on cool, dark night, light breeze, specimens sitting on gravel plains, sympatric with P. brevimanus , P. granulatus , O. jenseni , and O. wahlbergii (Thorell, 1876) , 2 ♂ (AMNH), 1 juvenile ♂ [AMCC (LP 9413)]; Ganab Station, 800 m east of Ganab road, 23°08′42.7″S, 15°30′54.3″E, 20.i.2009, L. Prendini, T.L. Bird & J. Huff, 1035 m, Central Namib gravel plains on north side of Tumasberg, low granite outcrops, dry riverbed, sandy-loam soil, gritty in places, UV detection on cool, dark night, light breeze, specimens sitting on gravel plains, sympatric with P. brevimanus , U. gracilior , Opistophthamus coetzeei Lamoral, 1979 and O. jenseni , 1 juvenile ♀ (AMNH), 1 juvenile ♀ [AMCC (LP 9416)]; Ganab VIP campsite, turnoff on Ganab road, 23°09′35.6″S, 15°31′10.9″E, 20.i.2009, L. Prendini, T.L. Bird & J. Huff, 1048 m, Central Namib gravel plains on east side of Tumasberg, Stipagrostis grassland with few granite outcrops, sandy-loam soil, UV detection on cool, dark night, light breeze, specimens sitting on gravel plains, sympatric with U. gracilior , O. jenseni , and O. wahlbergii , 1 ♂, 1 juvenile ♂ (AMNH); Gobabeb, gravel plains around camp and immediately on north bank of Kuiseb River, 23°33′36.2″S, 15°02′23.45″E, 19.i.2009, L. Prendini, T.L. Bird & J. Huff, 405 m, central Namib gravel plains, UV detection on cool, moonless night, slight breeze, syntopic with P. setiventer sp. nov., 2 ♂ (AMNH); 22 km from Gobabeb to Mirabib, 23°30′S, 15°11′E, 28.ii.1975, S. Endrödy-Younga, 1 subadult ♂ (TM 11087), 1 subadult ♂ (TM 11096); 52 km from Gobabeb on Mirabib road, 23°23′S, 15°31′E, 26.i.1975, S. Endrödy-Younga, 1 juvenile ♂ (TM 11117); Gorob Mine, quartz hill c. 500 m east, 23°34′11.6″S, 15°15′29.1″E, 20.i.2009, L. Prendini, T.L. Bird & J. Huff, 603 m, central Namib gravel plains with very sparse grass, Welwitschias in riverbed, soft, crumbly sandy-loam soil with high mica content, specimen taken from scrape under quartz stone on small rocky hill, syntopic with O. jenseni , 1 ♀ (AMNH); Langer Heinrich Mountain area, 22°48′40.9″S, 15°18′40.3″E, 27.ii.2006, Science EduVentures ‘06, 1 ♂ (SMN 2902 (EVS-1 P6-A)], 22°55′16.0″S, 15°17′44.7″E, 28.ii.2006, Science EduVentures ‘06, 704 m, UV detection, syntopic with Lisposoma elegans Lawrence (1928) and Uroplectes planimanus (Karsch, 1879) , 1 ♀, 1 subadult ♂, 2 subadult ♀, 2 juvenile ♂, 1 juvenile ♀ [SMN 2769 (SEV 06/03(a))], 22°48′49.2″S, 15°16′38.57″E, 1.iii.2006, Science EduVentures ‘06, 616 m, UV detection, syntopic with Opistophthalmus penrithorum Lamoral, 1979 and O. wahlbergii , 1 ♂, 1 ♀, 5 subadult ♂, 1 subadult ♀ [SMN 2752 (SEV 06/08(a))], 1 ♂ [SMN 2898 (SEV 06/08(a))], 1 ♂, 3 ♀ [SMN 2899 (SEV 06/05(a))], 22°53′57.4″S, 15°16′58.4″E, 2.iii.2006, Science EduVentures ‘06, 638 m, UV detection, syntopic with Hadogenes tityrus (Simon, 1888) , 1 ♂, 1 subadult ♂ [SMN 2897 (SEV 06/11)], 22°54′56.5″S, 15°17′40.2″E, 1.iii.2006, Science EduVentures ‘06, 701 m, UV detection, 1 subadult ♂ (SMN 2751), 2.iii.2006, Science EduVentures ‘06, 701 m, UV detection, 1 ♂, 1 subadult ♂ (SMN 2069); Langer Heinrich Mountain, gravel plains south, in Langer Heinrich Mining Lease area, 22°48′49.1″S, 15°17′47.3″E, 29.iii.2006, L. Prendini, T.L. Bird & S.K. Uunona, 639 m, UV detection on warm, still, dark night on Central Namib gravel plains with sparse grass, 3 ♂ (AMNH); between Langer Heinrich Berge and Scheifferberge, 22°50′24.8″S, 15°15′12.7″E, 29.iii.2006, L. Prendini, T.L. Bird & S.K. Uunona, 614 m, UV detection on warm, still, dark night on Central Namib gravel plains with granite outcrops and sparse grass, 1 juvenile ♂ (SMN 2896); Scheiffer Mountains, south-east, 22°54′47.6″S, 15°20′03.2″E, 29.i.2007, T.L. Bird, A. Klann, P. Michalik & G. Talarico, 742 m, UV detection, 1 juvenile ♂ [SMN 3075 (TB 06/202)]; Scheiffer Mountains, south-west, 22°54′15.3″S, 15°17′16.6″E, 29.i.2007, A. Klann, G. Talarico, P. Michalik & T.L. Bird, 685 m, 1 ♀ (SMN 3099), 1 ♀ (SMN 3101); Scheifferberge, 1 km northwest, 22°54′07.7″S, 15°17′04.6″E, 29.iii.2006, L. Prendini, T.L. Bird & S.K. Uunona, 679 m, UV detection on warm, still, dark night on Central Namib gravel plains with granite boulders and outcrops, and sparse Stipagrostis grassland on sandy patches in between, specimens collected on open sandy flats, sympatric with H. tityrus , 20 ♂, 4 ♀ (AMNH), 1 subadult ♂, 9 subadult ♀, 3 juvenile ♂, 1 juvenile ♀ (SMN 2900).

Diagnosis: Parabuthus glabrimanus sp. nov. is sister to the monophyletic group comprising P. gracilis , P. nanus , and P. setiventer sp. nov. ( Fig. 2 ). Parabuthus glabrimanus sp. nov. may be separated from these and all other species of Parabuthus by means of the following combination of characters: medium to small adult size, carapace length 5.0– 6.5 mm; carapace, including median ocular tubercle (male, female), with smooth areas; pedipalp chela movable finger of female short, compared with manus (measured along ventroexternal carina), length finger/length manus: ±1.40; pedipalp chela manus of adult male, noticeably incrassate, compared with that of adult female, which is slender; pedipalp chela manus surfaces smooth; pedipalp chela trichobothrium dt situated proximal to et; pedipalp femur and patella trichobothria d 2 present; sternites III–VII and metasomal segment I, ventral surfaces smooth, sparsely setose; metasomal segments slender (length IV/width IV: 1.7–2.11); metasomal segment I, ventrosubmedian carinae absent; metasomal segments II and III, posteroventral margins demarcated by transverse row of lobate granules; metasomal segment IV, acarinate; metasomal segments IV and V, lateral intercarinal surfaces granular; metasomal segment V, dorsosubmedian, dorsolateral and ventromedian carinae absent, ventrolateral carinae present, subparallel to converging posteriorly, and with posterior spiniform granules enlarged into lobate processes.

Etymology: The species name refers to the smooth, shiny chela manus that is characteristic of this species.

Description: The following description is based on the holotype male, two paratype males, and three paratype females ( Table 5).

Colour: Carapace, tergites and metasoma, base coloration: Buff-Yellow no. 53. Chelicerae, pedipalp chela, legs, sternites and telson slightly paler than carapace, pedipalp femur and patella, tergites and metasoma ( Fig. 8 ). Chelicerae, pedipalp chela and telson, base coloration: Cream no. 54. Legs and sternites, base coloration: Sulfur Yellow no. 157. Pectines: Pale Horn Color no. 92. The following surfaces strongly to weakly infuscated (Chestnut no. 32): chelicera manus, dorsal surface, distal margin; carapace interocular surface; pedipalp femur and patella, dorsointernal and dorsoexternal surfaces; leg femur, dorsoexternal and dorsointernal surfaces, distal third; post-tergites, posteromarginal surfaces; metasomal segments I and II, dorsal and dorsolateral surfaces, III, dorsal surface, anterior two-thirds, IV, dorsal surface, anterior third, IV, V, and telson, ventrolateral and ventral surfaces. Pale pedipalp chela contrasting with darker patella and femur. Metasoma dorsal surfaces becoming paler posteriorly (IV, V, and telson paler than I–III), ventral surfaces becoming darker posteriorly (IV, V, and telson darker than I–III).

Carapace: Carapace uniformly finely granular, granulation becoming coarser on interocular and posterolateral surfaces (♂), anterolateral, posterolateral, and posteromedian surfaces finely to coarsely granulation, circumocular, interocular, and posteromedian surfaces finely granular, with smooth areas (♀); superciliary carinae smooth. Anterior and posterior margins of carapace slightly procurved ( Fig. 5A, B ). Five pairs of lateral ocelli. Median ocelli considerably larger than lateral ocelli, situated anteromedially. Ocular tubercle with pair of smooth superciliary carinae, protruding slightly above median ocelli. Anteromedian sulcus shallow; posteromedian sulcus shallow anteriorly, becoming deeper posteriorly; posterolateral sulci shallow, wide, and curved; posteromarginal sulcus narrow, deep.

Chelicerae: Movable finger with distal external and distal internal teeth equal, opposable. Ventral aspect of fingers and manus with long, dense macrosetae. Fixed finger with pair of denticles on ventral surface.

Sternum: Type I, subtriangular ( Fig. 8B, D ). Median longitudinal furrow Y-shaped, shallow anteriorly, deep, narrow posteriorly.

Pedipalps: Pedipalps covered in short macrosetae ( Figs 9 , 10 ). Femur dorsal, internal, and external intercarinal surfaces uniformly, finely granular, ventral surface smooth (♂) or dorsal surface uniformly, finely granular, other intercarinal surfaces smooth (♀) ( Fig. 10C ); dorsointernal, dorsoexternal, and ventrointernal carinae distinct, granular; internomedian carina comprising discontinuous row of spiniform granules; externomedian carina obsolete, smooth; other carinae absent. Patella intercarinal surfaces uniformly, finely granular (♂) or internal intercarinal surfaces uniformly, finely granular, other surfaces smooth (♀) ( Fig. 10A, B ); dorsointernal and ventrointernal carinae obsolete, each comprising few granules proximally and distally; internomedian carina comprising prominent spiniform granule, proximally, and few smaller granules, distally; other carinae absent. Chela smooth ( Fig. 9B–E ); acarinate. Chela short, slender (♀), or markedly incrassate (♂), length along ventroexternal carina 27–38% greater than chela width and 33–46% greater than chela height ( Table 5); length of movable finger 14–20% (♂) or 34–40% (♀) greater than length along ventroexternal carina. Chela fixed and movable fingers straight, such that proximal dentate margin linear when fingers closed ( Fig. 9B–E ). Median denticle row of

Holo., holotype; Para., paratype.

*Sum of carapace, tergites I–VII, metasomal segments I–V, and telson.

†Sum of metasomal segments I–V and telson.

‡Measured from base of condyle to tip of fixed finger.

§Sinistral pecten damaged.

chela fixed and movable fingers, respectively, comprising eight and nine oblique primary subrows; each subrow comprising three to six small denticles and large external denticle, flanked by internal and external accessory denticles; terminal subrow of fixed finger shorter than others; basal subrow of fixed and movable fingers longer, comprising fusion of basal and sub-basal subrows; each finger with enlarged terminal denticle.

Trichobothria: Orthobothriotaxic, Type A, a configuration ( Figs 9B–E , 10 ), with following segment totals: femur, 11 (five dorsal, four internal, two external), patella, 13 (five dorsal, one internal, seven external) and chela, 15 (eight manus, seven fixed finger). Total number of trichobothria per pedipalp, 39. Femur d 2 present, situated on dorsal side of dorsointernal carina; e 1 situated level with or distal to d 5. Patella d 2 present; esb 2 situated slightly distal to esb 1. Chela Esb situated in line with or dorsal to Eb 2 – Et axis; eb situated proximal to basal dentate margin of fixed finger; dt situated proximal to et.

Mesosoma : Pre-tergites smooth, shiny, granular along posterior margins. Post-tergites entirely covered with uniform, fine granulation, becoming coarser posteriorly, especially along posterior margins (♂), anterolateral surfaces smooth, shiny, anteromedian surfaces uniformly, finely granular, posteromedian and posterolateral surfaces coarsely granular, especially along posterior margins (♀); I–VII each with weakly developed, costate dorsomedian carina; VII additionally with distinct pairs of costate-granular dorsosubmedian and dorsolateral carinae, and well-developed stridulatory surface between dorsosubmedian carinae, comprising rounded granules reaching posterior margin. Sternites III–VI, surfaces smooth, sparsely setose, lateral and posterior margins each with few macrosetae; VII acarinate, uniformly finely granular (♂) or smooth medially with sparse fine granules laterally (♀), sparsely setose, lateral and distal margins more densely so ( Fig. 6A ). Sternite VII, width 24–32% (♂) or 25–37% (♀) greater than length.

Pectines: First proximal median lamella of each pecten suboval, mesially enlarged, lobate in ♀ but not ♂ ( Fig. 8B, D ). Pectinal teeth: 29–31/28–31 (♂), 24–26/25–26 (♀) ( Table 5).

Genital operculum: Completely divided longitudinally. Genital papillae present (♂), absent (♀).

Legs: Tibiae III and IV with spurs; retrolateral margins with scattered macrosetae ( Fig. 11C, D ). Basitarsi I, II, and, to a lesser extent, III, dorsoventrally compressed, retrolateral margins each with dense row of long, fine macrosetae ( Fig. 11A–C ); III and IV, prolateral surfaces without dense tufts of macrosetae. Telotarsi each with paired ventrosubmedian rows of irregularly spaced macrosetae. Telotarsal laterodistal lobes truncated; median dorsal lobes extending to ungues. Telotarsal ungues long, distinctly curved, equal in length.

Metasoma and telson: Metasomal segments I–V width/length ratio progressively decreasing ( Table 5; Fig. 7A–C ), width percentage of length 67–73% (♂) or 74–79% (♀) for I, 56–64% (♂) or 62–70% (♀) for II, 55–57% (♂) or 57–61% (♀) for III, 46–51% (♂) or 50–58% (♀) for IV, and 46–50% (♂) or 48–55% (♀) for V. Telson oval, globose, height 50–62% (♂) or 52–72% (♀) of length, with flattened dorsal surface, rounded ventral surface; vesicle not distinctly narrower than metasomal segment V, width 70–79% (♂) or 74–90% (♀) of metasomal segment V. Aculeus short, sharply curved, 57–92% of vesicle length ( Table 5). Metasoma and telson 55–57% (♂) or 52–55% (♀) of total length. Metasoma intercarinal surfaces uniformly, finely granular, except segment V, dorsal surface, smooth and shiny (♂) or smooth and shiny, except segments I–V, dorsolateral and median lateral surfaces and segments IV and V, ventral and ventrolateral surfaces, finely granular, granulation becoming more pronounced posteriorly (♀); segments I–III, each with well-developed dorsal stridulatory surface, comprising fine rounded granules extending to posterior margin ( Fig. 7B, C ), less developed on segment III than I and II; II and III, posterodorsal edge sublinear. Metasoma sparsely to moderately covered with long acuminate macrosetae, especially on ventral surface of telson ( Fig. 7A ). Metasomal segments I–III each with ten carinae; IV acarinate; V with two carinae. Dorsosubmedian carinae distinct, converging posteriorly on segments I–III, absent on IV and V. Dorsolateral carinae distinct on segments I–III, absent on IV and V. Median lateral carinae distinct on segments I and II; obsolete on III; absent on IV and V. Ventrolateral carinae present, converging posteriorly on segments I–III, posterior section not forming U-shaped pattern on II and III; reduced to anterior row of isolated, rounded granules on IV; subparallel to converging posteriorly on V, with posterior spiniform granules enlarged into broad, lobate processes with flat surfaces apically ( Fig. 7A ). Ventrosubmedian carinae present on segments I–III; reduced to anterior row of isolated, rounded granules on IV; absent on V. All metasomal carinae costate-granular to granular, except for ventrosubmedian and ventrolateral carinae of segments I (♂, ♀) and II (♀), which are costate to costate-granular.

Hemispermatophore: Flagelliform, with pars recta parallel to axis of distal lamina ( Fig. 12 ).

Geographical variation: There is little morphological variation amongst specimens from different localities. However, striking variation in coloration is observed amongst specimens from the same locality. Variation in the intensity of infuscation is most obvious on the carapace, pedipalps, tergites, metasoma, and telson. Some specimens are darkly infuscated whereas others are pale. Pale specimens are not infuscated on the tergites and weakly so on the metasoma or devoid of infuscation altogether. Similar variation in coloration is observed in P. gracilis and P. nanus ( Lamoral, 1979; this study). Specimens from the two southern- and western-most localities, Gobabeb and Gorob Mine, are devoid of infuscation and the base colour is yellow, unlike specimens from further east, which are buff-yellow.

Ontogenetic variation: As in other species of Parabuthus , male resembles female very closely until the final instar ( Prendini, 2004a). Juveniles and subadults may be readily sexed by examination of the pectines and genital aperture.

Sexual dimorphism: Parabuthus glabrimanus sp. nov. is markedly dimorphic in several respects, most obviously in the shape of the pedipalp chela manus, and the structure of the pectines. As in most species of Parabuthus ( Prendini, 2004a) , the pedipalp chela manus of the adult male is markedly incrassate compared with that of adult female, which is more slender ( Fig. 9B–E , Table 5), and the first proximal median lamella of each pecten is suboval, mesially enlarged, and lobate in the female but unmodified in the male. The male has a higher pectinal tooth count (28–31) than the female (24–26). In addition, the adult male is proportionally more slender, with a slightly longer metasoma, than the adult female ( Fig. 8 , Table 5). The granulation and carination are also more pronounced. For example, the carapace of the male is entirely granular, whereas there are smooth surfaces on the carapace of the female ( Fig. 5A, B ).

Distribution: Endemic to the gravel plains of the Central Namib, north of the Kuiseb River, in the Erongo Region (Swakopmund District) of western Namibia ( Fig. 1 ). The known records fall within the range of 400–1100 m elevation. Parabuthus setiventer sp. nov. is more commonly found at lower elevations (300–450 m), further west. The known distribution of P. glabrimanus sp. nov. falls entirely within the boundaries of the Namib-Naukluft Park.

Ecology: Parabuthus glabrimanus sp. nov. is a psammophilous species, which displays several ecomorphological adaptations to its sandy habitat: elongated telotarsal ungues; basitarsi of legs I, II, and, to a lesser extent, III dorsoventrally compressed, with comb-like rows of long macrosetae (‘sand combs’) on the retrolateral margins ( Fig. 11A–C ); metasoma lacking carinae on segments III–V ( Fig. 7A ). Specimens of P. glabrimanus sp. nov. have been taken in pitfall traps and collected with UV light detection on warm, dark, still nights, resting on the surface of sandy to gritty substrata, on open gravel plains between granite outcrops. One specimen was collected from under a stone during daytime.

Parabuthus glabrimanus sp. nov. has been collected in sympatry with the following scorpion species: Bothriuridae : L. elegans ; Buthidae : P. brevimanus , P. granulatus , P. setiventer sp. nov., U. gracilior , and U. planimanus ; Liochelidae : H. tityrus ; Scorpionidae : O. coetzeei , O. jenseni , O. penrithorum , and O. wahlbergii . Its distribution is allopatric with those of the closely related species, P. gracilis and P. nanus ( Fig. 1 ). Parabuthus glabrimanus sp. nov. inhabits softer substrata than P. brevimanus .

PARABUTHUS GRACILIS LAMORAL, 1979

( FIGS 1–4 , 6B , 9A )

Parabuthus gracilis Lamoral, 1979: 566–571 , figs 96, 103, 104, 107–116; Kovařík, 1998: 116; Fet & Lowe, 2000: 202; Prendini, 2001b: 136; Prendini, 2001a: 17; Prendini, 2003: 20; Prendini, 2004a: 116, 143, 144, figs 1, 11, 26, 43; Prendini, 2005: 66, appendix 1; Prendini and Bird, 2008: 79, 80, 87–90, 93, 100, 103, 104, table 1, figs 2, 11.

Holotype: Namibia: Erongo Region: Omaruru District: Messum Crater area, 21°16′S, 14°13′E, 26.iii.1976, B. H. Lamoral & L. Ferguson, on surface of sandy to gritty soil at night, 1 ♀ ( NM 10925 ).

Paratypes: Namibia: Erongo Region: Omaruru District: Messum Crater area , 21°16′S, 14°13′E, 26.iii.1976, B. H . Lamoral & L . Ferguson, on surface of sandy to gritty soil at night, 8 ♂, 2 ♀, 4 juveniles ( NM 10848 ), 1 ♂ [ SMN 766 (ex NM 10848 )], 1 ♂ ( NM 10906 ). Swakopmund District : Cape Cross, 5 km north, 21°43′S, 13°56′E, 25.iii.1976, B. H . Lamoral & L . Ferguson , on surface of sandy to gritty soil at night, 2 ♂ ( NM 10854 ) . Kunene Region: Khorixas District: Skeleton Coast Park: Torra Bay , 30 km south-east, 20°23′S, 13°22′E, 30.iii.1976, B. H . Lamoral & L . Ferguson, on surface of dark brown gravel at night, 1 ♂, 1 juvenile ♂ ( NM 10860 ). Opuwo District: Skeleton Coast Park: Möwe Bay , 8 km north, 19°17′S, 12°42′E, 28.iii.1976, B. H . Lamoral & L . Ferguson, on surface of sandy ground with scattered rocks near high white sand dunes, 1 subadult ♀, 1 juvenile ♀ ( NM 10857 ); Möwe Bay , 4 km north, 19°19′S, 12°41′E, 29.iii.1976, B. H . Lamoral & L . Ferguson , on surface of rocky to gritty ground at night, 3 ♂, 1 ♀, 4 juveniles ( NM 10859 ) .

Diagnosis: Parabuthus gracilis is sister to the monophyletic group comprising P. nanus and P. setiventer sp. nov. ( Fig. 2 ). Parabuthus gracilis may be separated from these and all other species of Parabuthus by means of the following combination of characters: small adult size, carapace length 2.5– 5.0 mm; carapace, including median ocular tubercle (male, female), entirely granular; pedipalp chela movable finger of female short, compared with manus (measured along ventroexternal carina), length finger/length manus: ±1.50; pedipalp chela manus of adult male noticeably incrassate ( Fig. 9A ) compared with that of adult female, which is slender; pedipalp chela manus surfaces granular; pedipalp chela trichobothrium dt situated proximal to et; pedipalp femur and patella trichobothria d 2 absent or very reduced; sternites punctate; sternites III –VII and metasomal segment I, ventral surfaces moderately to sparsely setose ( Fig. 6B ); metasomal segments slender (length IV /width IV: 1.7–2.11); metasomal segments II and III, posteroventral margins demarcated by transverse row of isolated, round granules; metasomal segment IV, acarinate; metasomal segments IV and V, lateral intercarinal surfaces granular; metasomal segment V, dorsosubmedian, dorsolateral, and ventromedian carinae absent, ventrolateral carinae present, converging posteriorly, and with posterior spiniform granules enlarged into spinose processes.

Remarks: Compared with specimens from typical populations along the coast (e.g. Cape Cross, Messum Crater), specimens from inland populations (e.g. Bethanis, Twyfelfontein) are paler, less granular, and exhibit morphometric differences in the pedipalp chela and metasoma. The differences observed are not presently considered sufficient to merit recognition of the inland populations as a different species, but the matter is under further investigation from a molecular perspective.

Distribution: Endemic to sandy areas in the Central and Northern Namib, north of the Swakop River, in north-western Namibia ( Fig. 1 ). Recorded from the Erongo Region (Karibib, Omaruru, and Swakopmund districts) and the Kunene Region (Khorixas and Opuwo districts). The known records fall within the range of 0–600 m elevation. Parabuthus gracilis is protected in the Brandberg National Monument, the Cape Cross Seal Reserve, and the Skeleton Coast Park.

Ecology: Parabuthus gracilis is a psammophilous species, which displays several ecomorphological adaptations to its sandy habitat: elongated telotarsal ungues; basitarsi of legs I, II, and, to a lesser extent, III dorsoventrally compressed, with comb-like rows of long macrosetae (‘sand combs’) on the retrolateral margins; metasoma and telson lacking carinae on segments III – V. Specimens of P. gracilis have been taken in pitfall traps, collected at night with UV light detection, resting on the surface of sandy to gritty substrata, as well as unconsolidated white sand dunes, and excavated from burrows in shrub-coppice dunes.

Parabuthus gracilis has been collected in sympatry with the following scorpion species: Bothriuridae : L. elegans ; Buthidae : P. brevimanus , P. granulatus , Parabuthus kraepelini Werner, 1902 , P. namibensis Lamoral, 1979 , P. stridulus Hewitt, 1913 , U. gracilior , U. planimanus ; Uroplectes teretipes Lawrence, 1966 ; Scorpionidae : O. jenseni , O. penrithorum , and O. wahlbergii . Parabuthus gracilis is syntopic with P. namibensis and P. stridulus in the coastal part of its distributional range, and with P. brevimanus and P. granulatus inland ( Lamoral, 1979; Prendini, 2004a; Prendini & Bird, 2008). Parabuthus gracilis generally inhabits softer substrata than P. brevimanus and P. kraepelini . The distribution of P. gracilis is allopatric with those of the closely related species, P. glabrimanus sp. nov., P. nanus , and P. setiventer sp. nov. ( Fig. 1 ).

Additional material: Namibia: Erongo Region: Karibib District: Spitzkoppe, 21°49′S, 15°10′E, 18.xii.2000, Q. Martins, collected at night with UV light, sympatric with P. brevimanus , 1 ♂, 1 ♀ [ AMNH ( LP 1272)], 1 ♂ [ AMCC 159716 ( LP 1274)]. Omaruru District: Daweb ( N Uis), 4 km south, 21°03′S, 14°54′E, 6.ii.1981, A. Harington, on sandy and rocky areas, sympatric with L. elegans , P. granulatus , P. kraepelini , O. jenseni , and O. wahlbergii , 1 subadult ♂ [ AMNH ( AH 3386)], 2 subadult ♀ [ AMNH ( AH 3387, 3388)]; Messum Crater area, 21°25′S, 14°13′E, 21.i.1981, A. Harington, syntopic with P. brevimanus and U. gracilior , 1 ♂ [ AMNH ( AH 2164)]; Nai-Gap riverbed at northern tip of Uis mountains, 21°07′S, 14°52′E, 6.ii.1981, A. Harington, syntopic with P. brevimanus , 2 subadult ♂ [ AMNH ( AH 1917, 1918)]; Uis townlands, 21°15′S, 14°50′E, 2.ii.1981, A. Harington, 1 subadult ♂ [ AMNH ( AH 2167)]; Uis, 20 km from turnoff to Khorixas, 21°02′S, 14°54′E, 6.ii.1981, A. Harington, drizzling, specimens abundant on sand and near rocky surfaces, syntopic with P. granulatus , P. kraepelini , O. jenseni , and O. wahlbergii , 1 ♂ [ AMNH ( AH 2089)], 2 subadult ♂, 3 subadult ♀ [ AMNH ( AH 2090)]; Brandberg National Monument: Brandberg, base of hill 282, opposite Orabeskopf, 21°15′S, 14°38′E, 1.ii.1981, A. Harington, night collecting (cloudy sky, warm, windless) on sand-dune (soft, white but sometimes gritty soil) near hill, syntopic with P. granulatus , P. kraepelini , U. planimanus , and O. jenseni , 2 ♂ [ AMNH ( AH 2067, 2068)], 3 ♀ [ AMNH ( AH 2059, 2060, 2069)], 1 subadult ♂ [ AMNH ( AH 2061)], 1 subadult ♀ [ AMNH ( AH 2062)], 1 juvenile ♀ [ AMNH ( AH 2063)]; Brandberg, plains to south, opposite Orabeskopf, 21°15.48′S, 14°36.54′E, 16.i.1998, L. Prendini & E. Scott, collected at night with UV light, sympatric with P. brevimanus , 2 ♂ [ AMCC 119231 ( LP 1654)]. Swakopmund District: Cape Cross, 21°43′S, 13°58′E, 21.ii.1982, A. Harington, 2 ♂ [ AMNH ( AH 4397, 4404)], 1 ♀ [ AMNH ( AH 4398)]; Cape Cross, 21°45′53″S, 13°59′05.7″E, 18.i.2009, L. Prendini, T. L. Bird & J. Huff, 21 m, central Namib gravel plains, low rolling hills, and rock outcrops near Cape Cross seal colony, sandy-loam soil, UV detection on cool, moonless night, light breeze, specimens running on surface, syntopic with Uroplectes pilosus (Thorell, 1876) , 1 ♀ ( AMNH), 1 subadult ♂ [ AMCC ( LP 9367)]; Cape Cross, at entrance to seal colony, 21°45′40.7″S, 13°58′40.7″E, 18.i.2009, L. Prendini, T. L. Bird & J. Huff, 30 m, central Namib gravel plains, low rolling hills, and rock outcrops near Cape Cross seal colony, sandy-loam soil, UV detection on cool, moonless night, light breeze, specimens running on surface, syntopic with P. namibensis , U. pilosus , and O. penrithorum , 1 ♂, 1 ♀, 1 subadult ♂ ( AMNH); Cape Cross, 12.2 km south of turnoff on C 34, hills east of road, 21°49′34.4″S, 14°04′14.2″E, 18.i.2009, L. Prendini, T. L. Bird & J. Huff, 8 m, central Namib gravel plains, rocky hillslopes with no vegetation, sandy-loam to consolidated sand soil, UV detection on cool, moonless night, light breeze, syntopic with U. pilosus , 1 ♂ ( AMNH). Kunene Region: Khorixas District: Farm Bethanis 514, 20°24′S, 14°24′E, 17.xii.1988, A. Harington, 1 ♂ [ AMNH ( AH 4051)], 1 ♀ [ AMNH ( AH 4052)]; Khorixas, 25 km towards Uis, 20°30′S, 15°00′E, A. Harington, 1 subadult ♂ [ AMNH ( AH 3719)]; Twyfelfontein, 20°35′51.4″S, 14°22′15.1″E, 17.xi–23.xii.2003, T. L. Bird, 591 m, preservative pitfall traps, sandy plain, 1 ♂ ( SMN 2216), 20°35.729′S, 14°22.346′E, 21.i.2004, L. Prendini, E. Scott, T. & C. Bird, Q. & N. Martins, 592 m, 2 ♂, 2 ♀, 4 subadult ♂, 11 subadult ♀, 11 juvenile ♂, 8 juvenile ♀ ( AMNH), 1 ♀ [ AMCC 159717 ( LP 2636)], 20°35′51.6″S, 14°22′08.4″E, 6.ii.2007, T. L. Bird, A. Klann, P. Michalik & G. Talarico, 593 m, in valley, UV detection, 1 ♀ [ SMN 3094 ( TB 07/08 (a))].

PARABUTHUS NANUS LAMORAL, 1979

( FIGS 1–4 , 6C , 14A )

Parabuthus nanus Lamoral, 1979: 594–597 , figs 100– 102, 105, 106, 164–172; Kovařík, 1998: 117; Fet & Lowe, 2000: 208; Prendini, 2001b: 137; Prendini, 2001a: 17; Dyason et al., 2002: 769; Prendini, 2003: 21; Prendini, 2004a: 116, 162, 163, figs 1, 13, 44, 45; Prendini, 2005: 66, appendix 1.

Holotype: Namibia: Karas Region: Keetmanshoop District: Farm Noachabeb 97, 27°22′S, 18°22′E, 6.ii.1973,

B. H. Lamoral, found on rocky gravel ground at night, 1 ♀ ( NM 10926 ) .

Paratypes: Namibia: Karas Region: Karasburg District: Farm Belda 361, east side of Haib River , 28°28′S, 18°00′E, 28.i.1973, B. H . Lamoral , night collecting on sand dune, 1 ♂, 1 ♀, 2 subadult ♂ ( NM 10702 ), 28°27′S, 18°01′E, 1.ii.1973, B. H . Lamoral, 1 subadult ♂ [ SMN 764 (ex NM 10701 )]; Farm Louwshoop 330, 28°07′S, 18°07′E, 3.ii.1973, B. H . Lamoral & K . Porter, night collecting on sand dunes, 1 ♀ ( NM 10699 ). Keetmanshoop District: Farm Noachabeb 97, 27°22′S, 18°22′E, 6.ii.1973, B. H . Lamoral , night collecting with UV , found on rocky gravel ground, 1 ♂ ( NM 10926 ), 2 ♂ ( NM 10927 ); Farm Schwarzkuppen 104, Noachabeb, 27°23′S, 18°20′E, 8.ii.1973, B. H . Lamoral & K . Porter, night collecting on red sand dunes, 1 ♂, 1 subadult ♀, 1 juvenile ♂ ( NM 10698 ). Lüderitz District: Diamond Area 1: Farm Tsirub 13, 26°52′S, 16°02′E, 3.iii.1976, B. H . Lamoral , on rocky to sandy surface, marginal zone on lower reaches of mountain, 1 ♂, 1 ♀ ( NM 10772 ) . South Africa: Northern Cape Province: Namaqualand District: Goodhouse , 10 km south, 29°00′S, 18°13′E, 30.i.1973, B. H . Lamoral , night collecting, 1 ♀ ( NM 10700 ), 28°55′S, 18°14′E, 11.ii.1979, B. H . Lamoral, on northern margin of Koa valley, 2 ♀ ( NM 11304 ); Goodhouse , 21 km south, 29°04′S, 18°06′E, 29–31.i.1973, B. H . Lamoral , night collecting near mountain in plain, 1 ♂ ( NM 10703 ) .

Diagnosis: Parabuthus nanus is most closely related to P. setiventer sp. nov., the two species forming a monophyletic sister group to P. gracilis ( Fig. 2 ). Parabuthus nanus may be separated from P. setiventer sp. nov. and all other species of Parabuthus by means of the following combination of characters: small adult size, carapace length 2.5–5.0 mm; carapace, including median ocular tubercle (male, female), entirely granular; pedipalp chela movable finger of female long, compared with manus (measured along ventroexternal carina), length finger/length manus: 1.70–2.00; pedipalp chela manus of adult male, slender as in adult female ( Fig. 14A ); pedipalp chela manus surfaces granular; pedipalp chela with trichobothrium dt situated proximal to et; pedipalp femur and patella trichobothria d 2 absent or very reduced; sternites punctate; sternites III –VII, metasomal segment I and, to a lesser extent, II, ventral surfaces, densely covered in short, truncate macrosetae ( Fig. 6C ); metasomal segments slender (length IV /width IV: 1.7–2.11); metasomal segment I, ventrosubmedian carinae absent; metasomal segments II and III, posteroventral margins demarcated by transverse row of isolated, round granules; metasomal segment IV, acarinate; metasomal segments IV and V, lateral intercarinal surfaces granular; metasomal segment V, dorsosubmedian, dorsolateral, and ventromedian carinae absent, ventrolateral carinae present, converging distally, and with posterior spiniform granules enlarged into spinose processes.

Distribution: Endemic to sandy areas in the Karas Region (Bethanie, Karasburg, Keetmanshoop, and Lüderitz districts) of Namibia and the Northern Cape Province (Calvinia, Gordonia, Kenhardt, and Namaqualand districts) of South Africa ( Fig. 1 ). The distribution of this species extends across the Orange River. The known records fall within the range of 350–1250 m elevation. Parabuthus nanus is protected in the Ai-Ais and Fish River Canyon National Park, the Namib-Naukluft Park and the Sperrgebiet National Park.

Ecology: Parabuthus nanus is a psammophilous species, which displays several ecomorphological adaptations to its sandy habitat: elongated telotarsal ungues; basitarsi of legs I, II, and, to a lesser extent, III dorsoventrally compressed, with comb-like rows of long macrosetae (‘sand combs’) on the retrolateral margins; metasoma and telson lacking carinae on segments III – V. Specimens of P. nanus have been taken in pitfall traps, collected at night with UV light detection, resting on the surface of sandy-loam gravel plains, dry riverbeds and semi-consolidated to unconsolidated sand dunes, and excavated from burrows at the base of shrubs.

Parabuthus nanus has been collected in sympatry with the following scorpion species: Buthidae : Hottentotta arenaceus (Purcell, 1901) , Karasbergia methueni Hewitt, 1913 , P. brevimanus , P. capensis (Ehrenberg, 1831) , P. granulatus , Parabuthus laevifrons (Simon, 1888) , P. schlechteri , P. villosus , Uroplectes carinatus ( Pocock, 1890) , U. gracilior ; Liochelidae : Hadogenes zumpti Newlands & Cantrell, 1985 ; Scorpionidae : Opistophthalmus adustus Kraepelin, 1908 , Opistophthalmus carinatus (Peters, 1861) , Opistophthalmus haackei Lawrence, 1966 , and Opistophthalmus lornae Lamoral, 1979 and other Opistophthalmus species. Parabuthus nanus is syntopic with P. granulatus , P. laevifrons , and P. schlechteri throughout its distributional range. Where P. nanus and P. brevimanus are sympatric, the two species are not syntopic, however. Parabuthus nanus inhabits softer substrata than P. brevimanus ( Prendini, 2004a) . The distribution of P. nanus is allopatric with that of its sister species, P. setiventer sp. nov. ( Fig. 1 ).

Additional material: Namibia: Karas Region: Bethanie District: Farm Geigoab 95, 0.5 km west of intersection with D459 on road to Farm Blouputs 158, 27°10′44.1″S, 17°14′44.8″E, 4.ii.2008, L. Prendini & T. L. Bird, 826 m, arid savannah with Acacia woodland on flat sandy plain intersected by dry watercourses (Nuichas riverbed) and large stable alluvial sand dunes near base Nuichas Mountain, UV detection on hot, still, dark night after brief shower, specimens running on ground surface, sympatric with P. brevimanus , P. laevifrons , and P. schlechteri , 1 ♂, 1 ♀ ( AMNH). Karasburg District: Farm Haakiesdoorn 197, entrance gate, 28°44.306′S, 18°17.412′E, 18.i.2004, I. Engelbrecht & B. Watkins, 670 m, 1 ♀ ( AMNH), 1 ♀ [ AMCC 159719 ( LP 2484)]; Farm Komsberg 158, c. 55 km south of Ariamsvlei, 28°27.862′S, 19°44.065′E, 12.i.2004, I. Engelbrecht & B. Watkins, 1 ♂ ( AMNH); Farm Louwshoop 330, northern end, roadside next to main road, 28°03.379′S, 18°04.786′E, 16.i.2004, I. Engelbrecht & B. Watkins, 860 m, 1 ♂ ( AMNH); Farm Naroep 45, where road to Beenbreekberg crosses powerlines, 29°04.500′S, 18°34.200′E, 21.i.2004, I. Engelbrecht & B. Watkins, 1 ♂, 2 ♀ ( AMNH); Farm Witkop 36, 10 km south of Ariamsvlei, 28°12.034′S, 19°48.544′E, 11.i.2004, I. Engelbrecht & B. Watkins, 781 m, 6 ♂, 1 ♀ ( AMNH), 1 ♂ [ AMCC 159720 ( LP 2662)]; Grünau, south, c. 3 km north of C 10– B 1 road intersection, 27°53.847′S, 18°12.758′E, 16.i.2004, I. Engelbrecht & B. Watkins, 899 m, 1 ♂ ( AMNH); north of RTZ camp, 28°37′S, 17°49′E, 13–16.iv.1997, E. Griffin, gravel plains, preservative pitfall traps, 1 ♂ ( SMN 1725); Ai-Ais and Fish River Canyon National Park: Fish River Canyon, 0.3 km east of Ai-Ais on C 10 (Ai-Ais-Grünau), 27°55′09.5″S, 17°29′21.5″E, 5.ii.2008, L. Prendini & T. L. Bird, 502 m, alluvial sand dunes and flats on east bank of Fish River, tamarisk and Euclea pseudebenus Meyer, 1843 dominant trees, sparse grass and bushes, UV detection on hot, still, dark, humid night, specimens sitting/walking on open sand or small dunes, sympatric with Hottentotta arenaceus and P. brevimanus , 2 ♂, 6 ♀ ( AMNH), 1 subadult ♂, 1 juvenile ♂, 3 juvenile ♀ ( SMN 3304), 3 juvenile ♂ [ AMCC ( LP 8232)]. Keetmanshoop District: Farm Khabus 146, 26°18′S, 18°13′E, 14.iii–14.iv.1988, N. & P. G. Olivier, on sandy plain next to dry riverbed, preservative pitfall traps, 1 ex. ( SMN 1388), 14.iv–30.vi.1988, N. & P. G. Olivier, on sandy plain next to dry riverbed, preservative pitfall traps, 1 ♀ ( SMN 1415). Lüderitz District: Farm Gunsbewys 139, 26°11′56.16″S, 16°22′48.6″E, 5.i.2005, T. L. Bird, D. Kunz & B. Muramba, 1154 m, UV light, sand dunes, syntopic with O. adustus , 1 ♀ [ SMN 2913 ( TB 05/10)]; Farm Numis 89, 26°05′S, 16°12′E, 14.xii.2000, Q. Martins, collected at night with UV light, 1 ♂ [ AMNH ( LP 1269)]; Farm Numis 89, Tiras Mountains, 26°05′25.98″S, 16°13′02.46″E, 5.i.2005, T. L. Bird, D. Kunz, B. Muramba, 1128 m, UV light, 1 ♀ [ SMN 2581 ( TB 05/07)]; Farms Heinrichsfelde 10/Kubub 15 boundary, Geisterschlucht, 26°40.23′S, 16°13.47′E, 8.xii.2001, L. Prendini & C. Holmes, 1232 m, UV collecting, walking on sandy flats at night, 1 ♀ [ AMNH ( LP 1347)]; Diamond Area 2: Namib-Naukluft Park: Awasib plains, 25°25′S, 15°43′E, 26.ii.1981, G. Newlands, 1 ♂ [ AMNH ( AH 4345)]; Garub, 26°34′24″S, 16°02′37.2″E, 24–31.vii.2004, T. Greyling, pitfall trap BL2 A, 1 subadult ♂ ( SMN 2707), 26°38′57.6″S, 15°56′36.0″E, 12–19.viii.2004, T. Greyling, pitfall trap C 1 B, 1 ♂ ( SMN 2688). South Africa: Northern Cape Province: Calvinia District: Farm Eselkopvlakte, west-north-west of Loeriesfontein, 30°56′13″S, 19°01′09″E, 29.x–7.xi.2005, M. Burger, T. Felmore, E. Campher & J. S. Makokho, caught in pitfall and funnel traps, at trap SARCA 1–3, 1 ♀ ( AMNH), 1 juvenile ♂ [ AMCC ( LP 5806)]; Farm Ezelkopvlakte 333, near Kromrivier riverbed, plains near Sishen–Saldanha railway line, 30°55.948′S, 19°00.205′E, 26.ii.2009, L. Prendini & H. Bichard, 383 m, succulent karoo on Knersvlakte, flat undulating plain, cracked, clayey-loam soil with slightly reddish sandy surface covering, becoming much harder below surface, UV detection on cool, still, dark night, specimens sitting in open ground, syntopic with P. capensis , P. laevifrons , P. schlechteri , and U. carinatus , 1 ♂, 1 ♀ ( AMNH). Gordonia District: Farm Arrebees, Kakamas, 28°58′S, 20°07′E, 11.i.1995, A. Harington, 1 ♂ [ AMNH ( AH 2562)]; Farm Boegoeberg 48, north section, c. 55 km due east-south-east of Upington, 5 km south-west of Grootdrink, 28°37′54.6″S, 21°43′46.2″E, 20.xii.2006, M. Burger, I. Engelbrecht & R. Mercurio, 879 m, UV lighting (21:40–21:54), collected on open soil surface, sandy soil, storms in distance, gentle breeze (east direction), 75–99% cloud cover, no moon, 1 ♀ [ AMNH ( IE 06- 358)]; Riemvasmaak area, at entrance gate to Augrabies Falls National Park, 28°27.337′S, 20°19.835′E, 9–10.i.2004, I. Engelbrecht & B. Watkins, 684 m, pitfall trapping and UV detection in red sandy flats, 1 ♂ ( AMNH). Kenhardt District: Farm Oup 80, turnoff to Raap en Skraap from Kakamas–Onseepkans road, 28°50.699′S, 19°35′E, 26.i.2004, I. Engelbrecht & B. Watkins, 786 m, 1 ♂, 5 ♀ ( AMNH); Farm Skuitklip 92, 0.8 km south-east of intersection with road Pofadder–Raap-en-Skraap on road Onseepkans– Kakamas, 28°51.117′S, 19°35.375′E, 1.i.2008, L. Prendini & M. Cooper, 803 m, rocky hill with soft, red sand accumulated around base, surrounded by flat gravel plain, vegetation Stipagrostis grass tussocks and scattered Acacia mellifera Bentham, 1842 trees/bushes, UV detection on cool, dark, windy night, sitting/ walking on ground surface on plain, sympatric with P. granulatus , P. laevifrons , U. gracilior , Uroplectes sp. , and O. lornae , 1 ♀ ( AMNH); Farm Skuitklip 92, 2.5 km south-east of intersection with road Pofadder– Raap-en-Skraap on road Onseepkans–Kakamas, 28°51.324′S, 19°36.485′E, 1.i.2008, L. Prendini & M. Cooper, 821 m, steep rocky hills surrounded by grey sandy-loam gravel flats with grass tussocks and occasional bushes, dry riverbed and gravel plain with low rocky flats in places, UV detection on cool dark, windy night, sitting on gravel plain, sympatric with Karasbergia methueni , P. brevimanus , P. laevifrons , P. villosus , U. gracilior , and Opistophthalmus carinatus , 1 ♂, 1 juvenile ♀ ( AMNH); Farm Skuitklip 92, Eskom substation/red sand dunes, 3.5 km south-west of intersection with road Kakamas–Onseepkans on road Raap-en-skraap–Pofadder, 28°52.686′S, 19°34.003′E, 1.i.2008, L. Prendini & M. Cooper, 813 m, Stipagrostis grassland on semi-consolidated red sand dunes surrounded by red gravel plains, UV detection on warm, dark, windy night, specimens sitting on sand or bushes, seldom moving, at base of dune and on gravel plains, sympatric with Hottentotta arenaceus , P. granulatus , P. laevifrons , P. schlechteri , U. gracilior , and O. carinatus , 6 ♂, 2 ♀, 1 juvenile ♂ ( AMNH), 1 ♂, 1 juvenile ♂ [ AMCC ( LP 8231)]; Farm Skuitklip 92, hills and gravel flats at intersection of roads Kakamas–Onseepkans and Pofadder–Raap-en- Skraap, 28°50.831′S, 19°34.949′E, 1.i.2008, L. Prendini & M. Cooper, 784 m, grey sandy-loam gravel flats with grass tussocks and occasional bushes leading up to rocky hill where soil harder, more gritty, UV detection on warm, dark, windy night, specimen sitting on ground surface on gravel plain, sympatric with Karasbergia methueni , P. granulatus , P. laevifrons , and U. gracilior , 1 ♂ ( AMNH); Farm Skuitklip 92, red sandy flats at intersection with road Pofadder–Raap-en- Skraap on road Onseepkans–Kakamas, 28°50.966′S, 19°34.889′E, 1.i.2008, L. Prendini & M. Cooper, 791 m, flat gravel plain (grey to red sandy-loam soil) with Stipagrostis grass tussocks and scattered Acacia mellifera trees/bushes, UV detection on cool, dark, windy night, specimens walking on ground surface, sympatric with P. laevifrons and Uroplectes gracilior , 1 ♂, 1 ♀ ( AMNH). Namaqualand District: Aggeneys, 29°15′S, 18°50′E, 30.xii.1988, A. Harington, sandy, grassy flats, red sand, sympatric with P. granulatus and P. laevifrons , 1 ♀ [ AMNH ( AH 3695)], 1 ex. [ AMNH ( AH 4180)], ii.1997, L. Prendini, G. J. Müller et al., 2 ♂, 2 ♀ [ AMNH ( LP 820)], 3.xii.1997, L. Prendini & G. J. Müller, collected at night with UV light, 1 ♂, 2 ♀ [ AMCC 159718 ( LP 1653)], 6.xii.1997, L. Prendini, G. J. Müller et al., 1 ♂ [ AMNH ( LP 824)], 12.i.1999, G. J. Müller, J. J. van der Walt, J. Tytgat, J. du Plessis et al., 2 ♂ [ AMNH ( LP 471)]; Aggeneys, 10 km south, 29°18′S, 18°50′E, ii.1997, L. Prendini & G. J. Müller, 5 ♂, 2 ♀ [ AMNH ( LP 853)], ii.1997, L. Prendini, G. J. Müller et al., 7 ♂, 3 ♀ [ AMNH ( LP 796)], 4.xii.1997, L. Prendini, G. J. Müller et al., sympatric with U. gracilior , 1 ♂ [ AMNH ( LP 816)], 5.xii.1997, L. Prendini, G. J. Müller et al., sympatric with P. brevimanus 1 ♂, 2 ♀ [ AMNH ( LP 835)], 6.xii.1997, L. Prendini, G. J. Müller et al., 2 ♂, 1 ♀ [ AMNH ( LP 859)], 7.xii.1997, L. Prendini, G. J. Müller et al., 4 ♂ [ AMNH ( LP 823)]; Farm Aggeneys 56, Windpomp near Steneberg, south of R 64, 29°21.959′S, 18°51.274′E, 20.ii.2003, L. Prendini & E. Scott, 853 m, UV detection in Stipagrostis grassland on red sandy flats at base of quartzite outcrop, 1 ♀ ( AMNH); Farm Areb 75, west of Aggeneys, 29°30′04.6″S, 18°13′45.1″E, 12.ii.1995, A. Harington, 1 ♀ [ AMNH ( AH 2587)]; Farm Gemsbok Vlakte 140, c. 25 km north-east of Pofadder, 29°02.039′S, 19°37.423′E, 4.iii.2005, L. Prendini & E. Scott, 835 m, 8 ♂, 1 ♀ ( AMNH), 1 ♀ [ AMCC 159721 ( LP 4063)] Farm Goodhouse 23, dunes 500 m south of Vuurdoodberg on Pella–Concordia road, 28°59.034′S, 18°14.949′E, 21.ii.2003, L. Prendini & E. Scott, 481 m, 1 ♂ ( AMNH), 1 ♀ [ AMCC 159722 ( LP 4188)], 28°59.035′S, 18°14.597′E, 20.ii.2007, L. Prendini & J. Huff, 460 m, UV light detection in Stipagrostis grassland on semiconsolidated red sand dunes of Koa Valley system, sympatric with Hottentotta arenaceus , P. laevifrons , P. schlechteri , and Opistophthalmus sp. , 1 ♂ ( AMNH); Farm Goodhouse 23, 1 km west of turnoff to Goodhouse, on Pella–Concordia road, 28°58.684′S, 18°13.337′E, 2–3.iii.2005, L. Prendini & E. Scott, 450 m, succulent karoo on granitic sandy loam along dry watercourse and gravel flats, with hard igneous rocks interspersed with quartzite at base of large hill, UV detection on hot, dark, windy nights, becoming still later, specimens collected on gravel flats and dry watercourse, 1 ♂ ( AMNH), 28°58.904′S, 18°12.947′E, 20.ii.2007, L. Prendini & J. Huff, 479 m, UV light detection on warm, still, moonless night on sandy/gravel plains alongside rocky koppie, syntopic with P. brevimanus , P. granulatus , P. laevifrons , P. schlechteri , and Opistophthalmus spp. , 1 ♂ ( AMNH); Farm Steinkopf 22, dunes 1–2 km east of road Steinkopf–Henkries, turnoff 12–12.5 km north of turnoff to Jakkalswater, 29°02.582′S, 18°02.073′E, 24.ii.2003, L. Prendini & E. Scott, 578 m, 1 ♀, 1 juvenile ♀ ( AMNH), 1 ♂ [ AMCC 159723 ( LP 4191)].

Figures

Figure 1. Map showing the known distributions of Parabuthus glabrimanus sp. nov. (triangles), Parabuthus gracilis Lamoral, 1979 (squares), Parabuthus nanus Lamoral, 1979 (stars) and Parabuthus setiventer sp. nov. (circles) in Namibia and South Africa. Contour interval, 500 m. Major sand systems stippled. Magnified inset shows distributions of P. glabrimanus and P. setiventer in finer detail.

Figure 2. See Table 2 for details. The optimal tree retrieved by analyses with equal weights and implied weights under k = 3–6 (Table 2). This topology corresponds to the majority rule (> 50%) consensus of most parsimonious trees (MPTs) obtained by seven analyses in which weighting regime was varied; frequency percentages for nodes that collapsed in the strict consensus of the MPTs obtained by the seven analyses are indicated to the right of relevant nodes. Zero-length branches are collapsed. Solid bars indicate uniquely derived apomorphic character states, whereas empty bars indicate parallel derivations of apomorphic states under accelerated transformation (ACCTRAN) optimization. The number above each bar gives the character number, whereas the number below gives the character state. Branch support values are circled at nodes. Refer to Appendix for character descriptions. The East African species are indicated with asterisks. Alternative topologies for nodes A and B shown in Figures 3 and 4 respectively.

Figure 5. Parabuthus glabrimanus sp. nov. (A, B) and Parabuthus setiventer sp. nov. (C, D), carapace, dorsal aspect. A, holotype ♂ (SMN 2901). B, paratype ♀ (AMNH). C, holotype ♂ (SMN 2918). D, paratype ♀ (AMNH). Scale bars = 2 mm.

Figure 6. Parabuthus glabrimanus sp. nov. (A), Parabuthus gracilis Lamoral, 1979 (B), Parabuthus nanus Lamoral, 1979 (C) and Parabuthus setiventer sp. nov. (D), sternites III–VII, ventral aspect. A, ♂ [AMNH (AH 2164)]. B–D, ♂ (AMNH). Scale bars = 2 mm.

Figure 7. Parabuthus glabrimanus sp. nov. (A–C) and Parabuthus setiventer sp. nov. (D–F), metasoma and telson. A, D, ventral aspect. B, C, E, F, dorsal aspect. A, B, holotype ♂ (SMN 2901). C, paratype ♀ (AMNH). D, E, holotype ♂ (SMN 2918). F, paratype ♀ (AMNH). Scale bar = 2 mm.

Figure 8. Parabuthus glabrimanus sp. nov., habitus. A, B, holotype ♂ (SMN 2918). C, D, paratype ♀ (AMNH). A, C, dorsal aspect. B, D, ventral aspect. Scale bar = 10 mm.

Figure 9. Parabuthus gracilis Lamoral, 1979 (A) and Parabuthus glabrimanus sp. nov. (B–E), dextral pedipalp chela, illustrating trichobothrial distribution. A, ♂ [AMNH (AH 4397)], external aspect. B, holotype ♂ (SMN 2901), external aspect. C–E, paratype ♀ (AMNH), external (C), ventral (D), and internal (E) aspects. Scale bar = 1 mm.

Figure 10. Parabuthus glabrimanus sp. nov., paratype ♀ (AMNH), dextral pedipalp patella and femur, illustrating trichobothrial distribution. A, patella, dorsal aspect. B, patella, external aspect. C, femur, dorsal aspect. Scale bar = 1 mm.

Figure 11. Parabuthus glabrimanus sp. nov., paratype ♀ (AMNH), dextral legs I–IV, tibia, basitarsus, and telotarsus, retrolateral aspect, illustrating setae, ungues, and spurs. A, leg I. B, leg II. C, leg III. D, leg IV. Scale bar = 1 mm.

Figure 12. Parabuthus glabrimanus sp. nov., paratype ♂ (AMNH), dextral hemispermatophore, ental (A) and ectal (B) aspects. Scale bar = 2 mm.

Figure 14. Parabuthus nanus Lamoral, 1979 (A) and Parabuthus setiventer sp. nov. (B–E), dextral pedipalp chela, showing trichobothrial distribution. A, ♂ [AMNH (LP 1269)], external aspect. B, holotype ♂ (SMN 2918), external aspect. C–E, paratype ♀ (AMNH), external (C), ventral (D), and internal (E) aspects. Scale bar = 1 mm.