Rhopalurus pintoi Mello-Leitão, 1932

Teruel, Rolando & Tietz, Alexander K., 2008, The true identity of Rhopalurus pintoi Mello-Leitão, 1932, with notes on the status and distribution of Rhopalurus crassicauda Caporiacco, 1947 (Scorpiones: Buthidae), Euscorpius 70 (70), pp. 1-14 : 2-6

publication ID	https://doi.org/ 10.18590/euscorpius.2008.vol2008.iss70.1
publication LSID	lsid:zoobank.org:pub:2DF716C7-F789-41EA-9050-8E5C11D4A47C
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scientific name	Rhopalurus pintoi Mello-Leitão, 1932
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Figures 1–4 View Figure 1 View Figure 2 View Figure 3 View Figure 4 , 7–9 View Figure 7 View Figure 8 View Figure 9 , Tables 1–2

Rhopalurus pintoi Mello-Leitão, 1932: 11–12 , 14–15, 31, 38, 46, figs. 2a–c; Prado, 1939: 27, 36; Mello-Leitão, 1945: 266, 284–285, fig. 115 (in part); Lourenço, 1982: 107–108, 115, 117, fig. 78 (in part); Teruel, 2006: 51–52.

Rhopalurus laticauda pintoi: Lourenço, 1982: 107–108 , 115, 117–119, 121, 134–138, figs. 39–46, 78; table I (in part, references to the holotype only); Fet & Lowe, 2000: 220–221 (in part, references to the holotype only).

Rhopalurus piceus Lourenço & Pinto-da-Rocha, 1997: 181, 183–185, 187–191, figs. 4, 6, 8, 10, 12–13, 15–21, table I; Fet & Lowe, 2000: 221; Lourenço, 2002: 104–105, 110–111, 304–305, figs. 232–238; Lenarducci et al., 2005: 7, table II; Teruel, 2006: 52. New synonym.

Type data: Rhopalurus pintoi : ♀ holotype ( IOC, lost sensu Lourenço, 1982; see Remarks): Brazil, Roraima, Rio Tacutú, Brazilian border with Guyana. Rhopalurus piceus : Juvenile ♀ holotype (MZSP-15173, not examined; see Remarks): Brazil, Roraima, Tepequén , 15–22 June 1993, M. Vanzolini .

Diagnosis: species of large size (males 77–88 mm, females 84–91 mm) for the genus. Coloration entirely blackish, except only for white pectines and yellowish tips of legs and pedipalp fingers. Pedipalps densely hirsute and very slender in both sexes, with hands slightly more incrassate in males; fingers without basal lobe/ notch combination, but with weak scallop in adult males; fingers with 9–10 principal rows of granules, flanked by a many supernumerary granules. Carapace and tergites very strongly granulose. Sternite III and pectines with stridulatory apparatus well developed; sternite V with a vestigial smooth patch on males. Metasoma distally incrassate on both sexes, much more conspicuously in males; telson vesicle large, subaculear tubercle vestigial and close to the base of aculeus. Pectines with 27–30 (mode 28) teeth in males, and 21–25 (mode 24) in females; basal plate with a very large and deep pit in females.

Pectinal teeth Sex N Mean SD

21222324252627282930 ♂♂ 12 1 7 3 1 28.33 ± 0.78 ♀♀ 26 2 5 5 10 4 23.35 ± 1.20

Distribution ( Fig. 7 View Figure 7 ): this species appears to be endemic the Rupununi region comprising the border region of Brazil, Guyana and Venezuela. Specimens have been collected only from four localities in Brazil and one in Guyana, but it is probably present also in neighboring Venezuela (southern Bolivar State), where potentially suitable habitat also reaches.

Redescription (adult male from Rupununi): coloration ( Fig. 1 View Figure 1 ) basically dark yellowish to reddish brown, very densely spotted with blackish brown all over the boy and appendages so the entire scorpion looks black to unaided eye, except for the bright white pectines and yellowish tip of legs and pedipalp fingers. Carapace ( Fig. 2b View Figure 2 ) trapezoidal, slightly longer than wide and with all carinae present and coarsely granulose to denticulate: posterior median carinae almost fused to central lateral carinae (both carinae are aligned in straight row, but separate by a small gap of about one–granule length), central median carinae fused to lateral ocular carinae, superciliary carinae fused to anterior median carinae, posterior lateral carinae long and displaced forward to mid portion of carapace; tegument densely granulose and with many coarse granules scattered, much more densely on interocular triangle; median eyes separate by more than one ocular diameter; three pairs of lateral eyes, all relatively large and about the same size. Tergites ( Fig. 1a View Figure 1 ) with the same sculpture as on carapace; median carina very strong and coarsely granulose in all tergites; VII with two pairs of strongly granulose lateral carinae. Chelicerae ( Fig. 2b View Figure 2 ) with dentition typical for the genus; tegument smooth, polished. Pedipalps ( Figs. 1a–b View Figure 1 , 2a View Figure 2 ) orthobothriotaxic A-α, with all segments very slender (femur, patella, and chela each longer than carapace) and densely covered by long, reddish macrosetae. Femur with all carinae crenulate serrate to denticulate, intercarinal tegument densely granulose. Patella with all carinae crenulate to serrate, intercarinal tegument with the same granulation as on femur, internal surface with many large and spiniform granules. Chela oval and slightly incrassate, conspicuously wider than patella; hand with all carinae weakly to moderately granulose, intercarinal tegument coriaceous to finely granulose, with sparse coarser granulation; fingers densely hirsute and without basal lobe/notch combination, but with a weak scallop instead, extending almost the entire length of the fingers when closed. Both fixed and movable fingers with enlarged, clawlike tip and nine principal rows of granules, of which the basalmost is straight and very long (more than twice longer than the remaining), all rows flanked on each side by many supernumerary granules; tip of movable finger with complex dentition, composed of two subrows of four external and two internal granules just basal to distal tooth. Legs ( Figs. 1a–b View Figure 1 ) with all carinae granulose, intercarinal tegument coriaceous to finely granulose. Sternum ( Fig. 2c View Figure 2 ) type 1 and triangular, typical for the genus. Pectines ( Fig. 2c View Figure 2 ) elongate, with basal portion moderately enlarged; pectinal tooth count 28/28; basal plate wider than long, unmodified and with posterior margin slightly convex. Sternites ( Figs. 1a View Figure 1 , 2c View Figure 2 ) III–VI smooth and shiny, with sparse large punctations, spiracles elongate and slit-like; stridulatory apparatus well developed; posterior margin of sternite V with a moderately large smooth patch, which is much wider than long, light yellow and slightly bulky; sternite VII granulose, with two pairs of very long and strongly granulose lateral carinae. Metasoma ( Figs. 1a–b View Figure 1 , 2d–g View Figure 2 ) strongly incrassate distally, with each segment noticeably wider than the preceding, especially on IV–V which are inflate; intercarinal tegument coarsely and densely granulose on ventral and lateral surfaces, smooth to sparsely granulose on dorsal surface; segments I–II with ten complete carinae (even though lateral inframedian carinae is poorly defined in the basal portion of the latter), III–I V with eight, V with five (even though the ventrosubmedian carinae are present on proximal third), all strongly developed and coarsely serrate to denticulate; dorsomedian furrow shallow and narrow on segments I–III, progressively much deeper and wider on segments IV–V, specially on the latter where it becomes a deep subtriangular depression; telson with vesicle large, oval and smooth, subaculear tubercle vestigial and very close to the base of the aculeus, which is very long, sharp and shallowly curved.

Female ( Fig. 3 View Figure 3 , Tabs. 1–2): in general is similar to the male, but there is a marked sexual dimorphism evidenced by: (1) mesosoma relatively larger and wider; (2) metasoma less robust, only moderately incrassate distally; (3) pedipalp chelae noticeably more slender, with carinae stronger; (4) pedipalp fingers much longer and straight, without scallop; (5) genital papillae absent; (6) pectines with markedly lower number of teeth, which are also comparative smaller; (7) basal pectinal plate with a very large and deep discal pit.

Variation: among the examined adults there are two size classes in each sex but inside the same class, males are slightly smaller than females ( Tab. 1). Pedipalp fixed and movable fingers almost always have nine principal rows of granules, but in some specimens (mostly juveniles) the basalmost row is divided, giving a count of ten rows ( Fig. 3b View Figure 3 ). Pectinal toot counts varied from 27–30 (mode 28) in males, and 21–25 (mode 25) in females ( Tab. 2); this species is unique in the genus by the strong sexual dimorphism in pectinal tooth counts (male and female ranges entirely separated), and male counts represent the highest values amongst all Rhopalurus species. Juveniles are very similar to the adults in coloration and general morphology, but comparatively have much more slender pedipalps and less incrassate metasoma ( Fig. 4 View Figure 4 ).

Ecological notes: according to the collector of the samples available to us, about 20 specimens were found, all under stones inside a small relict patch (100 x 100 m) of primary forest enclaved inside surrounding hilly grasslands on volcanic soils ( Fig. 8 View Figure 8 ). Only single specimens were found per stone, at an approximate density of four scorpions per 10 m 2, sympatrically with a single specimen of R. crassicauda .