Brachistosternus paposo, Ojanguren-Affilastro, Andrés A. & Pizarro-Araya, Jaime, 2014

Ojanguren-Affilastro, Andrés A. & Pizarro-Araya, Jaime, 2014, Two new scorpion species from Paposo, in the Coastal desert of Taltal, Chile (Scorpiones, Bothriuridae, Brachistosternus), Zootaxa 3785 (3), pp. 400-418 : 401-410

publication ID 10.11646/zootaxa.3785.3.4

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scientific name

Brachistosternus paposo

sp. nov.

Brachistosternus paposo View in CoL n. sp.

( Figs. 1 View FIGURE 1 , 2 View FIGURES 2, 3. 2 , 4–9 View FIGURES 4 – 11. 4 – 9 , 12–23 View FIGURES 12 – 19 View FIGURES 20 – 23 ; Table 1 View TABLE 1 )

Type material. Holotype ♂: Chile, Antofagasta Region, 4.4 km N. from the village of Paposo (24°58'11'' S, 70°28'30'' W), 1 m asl, (dunes in beach), 22-27/X/2011. A. A. Ojanguren-Affilastro, J. Pizarro-Araya, D. Valdivia, F. Alfaro Kong, J. E. Barriga Tuñón, S. Rothman Toro, J. Mondaca & M. Ramírez coll. ( MNHN); Paratypes (same data as holotype): 1 ♀ ( MNHN); 3 ♂, 1 ♀, 3 juv. ( MACN); 1 ♂, 2 juv. ( MZUC); 1 ♂ ( LEULS).

Etymology. The name of this species refers to the type locality, Paposo , a small protected area in Antofagasta Region, in Northern Chile, and is used as a noun in apposition.

Diagnosis. Brachistosternus paposo n. sp. is most closely related to Brachistosternus roigalsinai Ojanguren- Affilastro 2002, both species can be separated because the distal lamina of the hemispermatophore of B. roigalsinai is almost straight, and in the same line with the basal portion ( Figs. 10, 11 View FIGURES 4 – 11. 4 – 9 ), whereas in B. paposo n. sp. the upper part of the distal lamina is conspicuously inclined internally ( Figs. 8, 9 View FIGURES 4 – 11. 4 – 9 ). The Distal Lamina of the hemispermatophore is proportionally narrower in the base of the apex in B. paposo n. sp. than in B. roigalsinai , the ratio between the total length of the distal lamina and the width of the base of the apex ranges between 7.54–9.15 (N=5; mean=8.25) in B. paposo n. sp. whereas in B. roigalsinai it ranges between 5.64–7.4 (N=9; mean=6.89). Other apparent differences in the shape of the hemispermatophores of these two species are not reflected in measurements.

Brachistosternus paposo n. sp. specimens are smaller than B. roigalsinai , being the total length 46–50.5 mm in ♂ of B. paposo ; and 47–55 mm in ♀; whereas in B. roigalsinai males it is 52–77 mm, and in females it is 61–95 mm.

Brachistosternus paposo Brachistosternus barrigai Description. Based on the holotype ♂ (MNHN) and paratypes (MACN, LEULS, MZUC). Total length: 46– 50.5 mm in ♂ (N=5; mean= 48 mm); 47–55 mm in ♀ (N=5; mean= 51 mm). Colour: Base colour light yellowish, with dark brown, almost black, pigmentation pattern ( Figs. 20–23 View FIGURES 20 – 23 ) in carapace and tergites, the remaining light yellowish; in some specimens there is a barely visible, light brownish pattern in metasoma and legs. Chelicerae light yellow. Carapace, with two broad dark stripes from the postocular furrow to the lateral margins, leaving a small triangular unpigmented area in the anterior margin, that does not reach the ocular tubercle nor the lateral eyes; with two small posterolateral dark spots. Tergites I–VI each with two well-developed lateral dark spots, and a median small anterior dark spot; most usually these spots are connected forming a single dark stripe. Tergite VII with two faint little lateral dark spots, and with brownish reticular pattern in posterior margins. Sternites, sternum, genital opercula and pectines unpigmented. Metasomal segments I–IV unpigmented or with a light brownish stripe over the LM carina, with a Dorsal Median brownish stripe, and with faint brownish reticular pattern in the dorsolateral margins; metasomal segment V unpigmented or ventrally with VM, VSM and VL stripes joining in the posterior half of the segment, lateral margins with a lateral median stripe. Telson , vesicle unpigmented, acculeus dark brown. Pedipalps: usually completely unpigmented, but in some specimens some areas with a light brownish pattern in femur and patella; femur with a light brownish pattern dorsally and a brownish stripe along external margin. Patella, with dorsal and ventral margins pigmented, with an external stripe. Legs: unpigmented or with a light brownish pattern in the distal half of femur and in patella. Chelicerae: with two subdistal teeth. Carapace: anterior margin convex and with a well developed median projection. Surface: in females lateral margins slightly granular, median area almost smooth; in males lateral margins coarsely granular, median area finely granular. Anterior longitudinal sulcus, posterior longitudinal sulcus, and lateral sulci present and well developed. Median ocular tubercle pronounced placed in the middle of the carapace, interocular sulcus present, median ocelli medium sized, ca two diameters apart; with one seta behind each eye. Three small lateral ocelli on each side of carapace. Tergites: Surfaces, I–VI: finely granular specially in posterior and lateral margins, more densely in males; VII with paired submedian and lateral carinae; lateral carinae restricted to posterior two-thirds of segment, submedian carinae restricted to the posterior half of the segment, intercarinal surfaces with scattered medium-sized granules, rest of surface finely granular. Sternites: Surface smooth in females, coarsely granular in males, more densely in its median part, III–VI with large and elongated spiracles. Metasoma: Metasomal segment I, dorsal surface densely granular, except for the anterior-median area that is almost smooth; DL and LM carinae well developed, granular, with no elevation of the tegument, extending entire length of segment, in some specimens with one DL macrosetae; lateral surface granular, except for the area between LM and LIM carinae, which is almost completely smooth, LIM carinae barely visible between the granulation, occupying the posterior half of the segment and joining medially with the LM carina, LM carina with one macroseta in its median part, LIM carina with one macroseta in its posterior third; ventral surface with coarse blunt granules in males, smooth in females, VL carinae absent or reduced to a barely visible elevation of the tegument, each with two macrosetae; with no VSM nor VM carinae, with one pair of VSM macrosetae on the distal margin of the segment. Metasomal segments II and III: similar to segment I, but less granular and with less developed carinae. Metasomal segment IV: dorsal surface granular, except for the median area, DL carinae granular, extending the entire length of the segment; with one macroseta; LSM carina absent, LM carina visible in males, obsolete in females, with two macrosetae; LIM carina absent, lateral and ventral margins smooth; ventral surface with scattered setae, VM carinae are barely discernible by a slight elevation of the tegument only in highly granular males, otherwise these carinae are obsolete. Segment V elongated ( Figs. 4, 5 View FIGURES 4 – 11. 4 – 9 ); length/width ratio: 1.65–1.82 in ♂, 1.79–1.9 in ♀; dorsal surface smooth, males with two very well developed glands or androvestigia ( Cekalovic 1973) occupying most of the surface of the length of the segment, DL carinae extending the entire length of the segment in males, and restricted to the anterior third in females, with 1 macroseta; dorsolateral surface granular in males, smooth in females, LSM carinae not visible, LM carinae obsolete in females, granular in males, with six or seven macrosetae, and a similar number of microsetae; ventral surface with scattered granules, more so in the posterior third of the segment, usually with three transversal rows of macrosetae, one near the anterior margin of four macrosetae, and two of two macrosetae each in the median part of the segment (distribution 4-2-2); VL carinae granular, straight, and extending the entire length of the segment with 7 to 10 VL macrosetae (N=10; Median=9), VM carina granular, extending the entire length of the segment, and getting broader in the posterior third. Telson: Vesicle , globose, more so in females; lateral and ventral margins with blunt granules in males, smooth in females; dorsally with two VSM furrows, laterally with a conspicuous furrow on each side; dorso-lateral surface granular in males, dorsal surface smooth and shallow, in males there is no conspicuous glandular surface. Aculeus longer than the vesicle, shallowly curved; more so in females ( Figs. 6, 7 View FIGURES 4 – 11. 4 – 9 ). Pedipalps: Femur ( Fig. 19 View FIGURES 12 – 19 ) with DI, DE, and VI carinae granular, extending entire length of segment; anterior margin with scattered coarse granules and two macrosetae, one basal and one placed medially; rest of the intercarinal surfaces smooth. Patella ( Figs. 17, 18 View FIGURES 12 – 19 ) with DI and VI carinae granular, extending entire length of segment; rest of the segment smooth, with three anterior macrosetae. Chela manus ( Figs. 12–16 View FIGURES 12 – 19 ) slender, slightly more robust in ♂, length/width ratio varies between 4.63–4.79 (N=5; mean=4.71) in ♂, and between 4– 4.25 (N=5; mean=4.14) in ♀; the length/height ratio varies between 3.44–3.64 (N=5; mean=3.54) in ♂, and between 3.14–3.26 (N=5; mean=3.21) in ♀; with a blunt VM accessory carina,

internal surface with slight bulge near articulation of movable finger (♀), or with a pronounced, subtriangular projection (♂); fingers elongated, with a median row of denticles, and with eight or nine pairs of accessory denticles, being the basal external denticle usually part of the median row. Trichobothrial pattern neobothriotaxic major Type C, with one accessory trichobothrium in V series of chela; femur with 3 trichobothria (d, i, e), one macroseta (M1) associated with d and i, e situated in same axis as, or slightly proximal to M; patella, with 19 trichobothria (2 d, i, 3 et, est, 2 em, 2 esb, 5 eb, 3 V); chela with 27 trichobothria (Dt, Db, 5 Et, Est, Esb, 3 Eb, dt, dst, dsb, db, et, est, esb, eb, ib, it, 5 V), Esb forming triangle with Eb 1 and Eb 2. Pectines: Tooth count: 32–33 in ♀ (N=5; Median=33); 35–39 in ♂ (N=5; Median=37). Legs: Surfaces smooth, except for the femur of legs II-IV which is granular in males; ventrally with two incomplete carinae. Basitarsi each with two well developed, almost equal length pedal spurs, being the internal one slightly smaller. Telotarsi elongated and ventrollaterally compressed, dorsally with a row of setae, ventrally each with a ventromedian row of poorly developed hyaline setae, and paired rows of ventrosubmedian setae. Counts of setae on telotarsus of leg III: Dorsal setae: 10–12 (N=10; median=12); ventrosubmedian, prolateral setae: 6–7 (N=10; median=7); ventrosubmedian, retrolateral setae: 5–6 (N=10; median=6). Ungues slightly curved, equal in length. Hemispermatophore: ( Figs. 8, 9 View FIGURES 4 – 11. 4 – 9 ) right and left hemispermatophores asymmetrical as in the rest of the species of the genus. Left hemispermatophore: Basal portion well developed. Distal lamina very well developed, longer than the basal portion; apex elongated and inclined towards the internal margin, distal lobe (distal posterior flexure) very elongated, occupying almost the basal half of the distal lamina; cylindrical apophysis of the basal lobe very well developed, very thick in its median part, with an acute and curved tip, and reaching the basal half of the distal lobe, much longer than the laminar apophysis; row of spines and basal spines well developed and in the same line, internal spines absent; basal triangle very well developed formed by three or four chitinous crests. Right hemispermatophore without a cylindrical apophysis, instead there is secondary laminar apophysis, one third longer than the laminar apophysis; the rest as left hemispermatophore.

Distribution. This species has only been collected in its type locality in the coastal area close to the village of Paposo , in the coast of Southern Antofagasta Region ( Fig. 1 View FIGURE 1 ).

Ecology. The area where this species has been collected belongs to the “Desierto Costero de Taltal”, of the “Desierto Costero” Botanical region. This species has only been collected in coastal environments, in areas with substrate formed mostly by sand, and with some small rocks. Brachistosternus paposo n. sp. was collected in an environment higher than the sea shore level, associated to the following plant species Copiapoa cinerea (Phil.) Britton & Rose , Eulychnia iquiquensis (K.Schum.) Britton & Rose , Nolana sp., Lycium deserti Phil. , Euphorbia lactiflua Phil. , Cristaria integerrima Phil. and Perityle emoryi Torr ( Fig. 2 View FIGURES 2, 3. 2 ).

The only known specimens of B. paposo n. sp. have been collected in spring, which suggests that this species has a spring-summer activity period, as most known species of Brachistosternus .

This species has only been collected in sympatry with Brachistosternus barrigai n. sp.

TABLE 1. Measurements (mm) of Brachistosternus paposo n. sp. (holotype and paratype, MNHN) and Brachistosternus barrigai n. sp. (holotype and paratype, MNHN).

  Holotype ♂ MNHN Paratype ♀ MNHN Holotype ♂ MNHN Paratype ♀ MNHN
Total length Carapace, length Carapace, anterior width 43.82 5.01 3.39 51.86 6.55 4.69 43.63 5.82 4.04 45.69 5.66 4.04
Carapace, posterior width Mesosoma, total length Metasoma, total length 5.09 13.2 20.12 6.46 14.2 24.24 6.14 14.03 23.23 6.1 16.1 18.43
Metasomal segment I, length Metasomal segment I, width Metasomal segment I, height 3.31 3.15 2.42 3.96 4.04 3.15 4 4 3.31 2.83 4.3 3.47
Metasomal segment II, length Metasomal segment II, width Metasomal segment II, height 3.88 2.91 2.59 4.44 3.8 3.15 4.2 3.72 3.31 3.23 3.15 2.75
Metasomal segment III, length Metasomal segment III, width Metasomal segment III, height 3.96 2.75 2.67 4.85 3.55 3.15 4.28 3.55 3.23 3.72 2.99 2.59
Metasomal segment IV, length Metasomal segment IV, width Metasomal segment IV, height 4.12 2.59 2.34 5.09 3.23 2.83 4.85 3.56 3.15 3.8 2.91 4.89
Metasomal segment V, length Metasomal segment V, width Metasomal segment V, height 4.85 2.75 2.26 5.9 3.15 2.5 5.9 3.55 2.75 4.85 2.83 2.26
Telson , length Vesicle, length Vesicle, width 5.49 2.83 2.18 6.87 3.39 2.34 6.55 3.56 2.59 5.5 2.99 2.26
Vesicle, height Aculeus, length Femur, length 1.65 2.67 4.2 2.1 3.47 4.04 2.34 2.99 4.53 1.94 2.51 3.64
Femur, width Patella, length Patella, width 1.21 3.96 1.45 1.54 3.88 2.02 1.29 4.12 1.62 1.29 3.47 1.54
Chela, length Chela, width Chela, height 7.03 1.54 1.94 7.7 1.73 2.34 8.48 2.18 2.83 6.79 1.62 2
Movable finger length 4.04 4.4 5.09 3.8

Museum National d'Histoire Naturelle


Museo Argentino de Ciencias Naturales Bernardino Rivadavia


Universita di Cagliari

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