Scotinoecus major, T, Duniesky Rios & Goloboff, Pablo A., 2012

T, Duniesky Rios & Goloboff, Pablo A., 2012, New species of Chilean Hexathelidae (Araneae, Mygalomorphae), Zootaxa 3422, pp. 32-51 : 39-40

Scotinoecus major sp. nov.

Figs 5–6 ; 15; 21–24

Scotinoecus cinereopilosus Calderón, 1973: 238 , figs 1–7 (3 only, missidentified).

Type. Female holotype ( MNHN 6808), from Quebrada Córdoba [33°29'22"S 71°37'49"W], Valparaiso, Chile. 6 Feb 1992 (P. Goloboff–N. Platnick–M. Ramírez).

Etymology. The specific epithet refers to the size of this species, the largest in the genus.

Diagnosis. It is distinguished from the other species in the genus by the larger spermathecae, more strongly sclerotized at the base, by having fewer spines on the anterior tarsi, and by the wider sternum (width: length ratio, 0.914). From S. cinereopilosus , it is further distinguished by lacking a dark marginal band on the sternum and the larger ALS (as big as the PMS) with 4 spigots, instead of only 1 or 2.

Description (Female holotype). Total length 14.40, cephalothorax length 4.92, width 3.96; pars cephalica length 3.12, width 3.12; ALE largest, both eye rows recurved, with group of 10 setae in front of OQ and 6 setae behind; series of 10–11 setae along midline, with 2 longer setae in front of fovea. Chelicerae with 9 large teeth on promargin, with ca. 40 denticles in fang furrow (11 denticles along posterior edge of this group of denticles larger than rest, almost resemble row of retromarginal teeth); palpal coxae with ca. 95 cuspules, and dense scopula of reddish hairs along anterior margin; labium length 0.72, width 1.12, with ca. 75 cuspules and 17 long setae on anterior margin. Sternum wide, length 2.80, width 2.56. Opisthosoma globose, length 6.6, dark brown with small mottling forming chevron of curved lines. Spinnerets long, PLS with basal: medial: apical articles of lengths 1.52: 1.00: 1.60; PMS length 0.80; ALS biarticulate, with basal: apical segments of lengths 0.48: 0.36; apical article of ALS conic, with 4 spigots; PMS and ALS about same size. Chaetotaxy: Femora: I, II, IV and palp, with series of 6 d along midline (middle and apical thickest); I, IV, 1 p a; III, long thick dorsal setae, 1 p sup, 1 r a, 1–1–0 d ant, 0–1– 1 d post. Patellae: I, 1 p a; II, 1–1 p m; III, 0–1–1 p sup, 1–1–0 r sup; IV, 1 r m; palp, 1 d m. Tibiae: I, 1 P M, 2 V A ANT, 1–1– 1 V POST; II, 1 P M, 2 V A ANT, 1–1– 1 V POST; III, 1–1 R SUP, 1–1 P SUP, 1–1– 1 V POST, 1–2– 2 V ANT; IV, 1–1 R SUP, 1 P M, 0–1–1– 2 V ANT, 0–1– 1 V POST; palp, 1–1– 2 V ANT, 1–1– 2 V POST, 1 P M. Metatarsi: I, 1–1– 1 V ANT, 1–1– 1 V POST, 1 V A, with 2 apical preening combs (of 2 or 3 bristles); II, 1–1–1 P SUP, 1–1– 1 V ANT, 1–1– 1 V POST, 1 V A, with 3 apical preening combs (of 2–2–3 bristles); III, 1–1–0–1 R SUP, 1–1– 1–1 P SUP, 1–1–0– 1 V POST, 1–1–1– 1 V ANT, with 3 apical preening combs (of 4–2–4 bristles); IV, 0–1–0–1 R SUP, 0–1–1–1 P SUP, 0–1–0– 1 V POST, 1–1–1–1– 1 V ANT, with 2 apical preening combs (of 3–5 bristles). Tarsi: I, 1/1–1 P INF, 0/1 R INF; II, 1–1–1–2 P INF, 1–1–1 R INF, 1 V MED (left leg), or 1–1–1–1–1–1 P INF, 1 R INF (right leg); III, 0–1–1–1 P INF, 1 V M, 1–1–1 R INF; IV, 0–1–1–1 P INF, 1–2–1–1 R INF; palp, 1–1–1–1–1 P INF, 1 V M, 0–1–0–2–1 R INF. Trichobothria: Tarsi I–IV with 8; metatarsi I–III with 11, IV with 18; tibiae with 2 rows of 7.

Variation in other females. Femora: III, 1–1 p sup. Patellae: II, 1–1 p; Tibiae: II, 1–1 P SUP, 0–1– 2 V ANT; III, 1–2– 2 V ANT, 1–1– 1 V POST; IV, 1–0–1–0 R SUP, 1–0–1–0 P SUP, 2 V ANT, 1– 1V B, 0–1–0– 1 V POST; palp, 1–1–1– 2 V ANT. Metatarsi: II, 0–1–0–1 P SUP, 1–1–1– 1 V ANT, 1–1–1– 1 V POST, with 2 apical preening combs (of 2–3 bristles); III, 2–1–1–1– 1 V ANT, 1 V A, 1–1–0–1– 1 V POST, 1–0–1 R SUP, with 3 apical preening combs (of 2–3–3 bristles); IV, 2–1–1–1– 1 V ANT, 1–1–0– 1 V POST, with 2 apical preening combs (of 3–2 bristles). Tarsi: I, 1–1 P INF, 1 R INF; II, 1–1–1 P INF; IV, 1–1–1 R INF.

Male. Described by Calderón (1973) as the male of Scotinoecus cinereopilosus .

Other specimens examined. Chile. Región V (Valparaiso): San Antonio: Quebrada Córdoba, 5 km E. El Tabo [33°29'22"S 71°37'49"W], 6 Feb 1992 (P. Goloboff – N. Platnick – M. Ramírez) 4 Ƥ ( MACN) 1Ƥ ( AMNH). Región VII (del Maule): Linares : El Peñasco (21 km SE Linares ) ~ 200 m. a.s.l. [36° 1'35"S 71°32'48"W], 8 Feb 1992 (P. Goloboff – N. Platnick – M. Ramírez) 6 Ƥ ( MACN) 1Ƥ ( AMNH). 16.3 km. E. Linares [35°50'58"S 71°25'15"W], 8 Feb 1992 (M. Ramírez – N. Platnick – P. Goloboff) 6 Ƥ ( MACN).

Distribution and habitat. Regions V and VII. The specimens were collected from sheet webs that were larger than in other species. Retreats were often at the base of plants or grasses; webs seemed more aerial than in other species, resembling those of Ischnothele (see Coyle 1995, figs. 4–6). The type and specimens from Linares Province come from localities separated by about 250 km. Although Linares is situated in a different biogeographical region, the specimens from El Peñasco were collected on banks and hills where the vegetation was more scrubby than typical for the region; specimens of Calathotarsus ( Migidae , a genus typical from Central Chile, and collected as well in Quebrada Córdoba) were also collected there (see comments on natural history of Acanthogonatus peniasco in Goloboff, 1995, p. 109). The specimens from 16.3 km E Linares were collected in the more typical vegetation of the region. Despite some morphological differences, specimens from all three localities agree in essential details –including the group of denticles in the fang furrow with those denticles along the posterior edge enlarged, and the large ALS with more numerous spigots– and thus all are concluded to be conspecific.

Figures

FIGURES 1 – 6. Female Scotinoecus. Sternum and maxillae, and spinnerets. 1 – 2. S. cinereopilosus. 3 – 4. S. ruiles sp. nov. 5 – 6. S. major sp. nov.