Mediothele minima, 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 : 42-44

Mediothele minima sp. nov.

Figures 33–38

Types. Female holotype (6809 MNHN) from Casablanca [33°19'14"S 71°24'25"W], Valparaiso, Chile, 8 Jan 1984 (P. Goloboff).

Etymology. The specific epithet refers to the small size of this species.

Diagnosis. M. minima is the smallest species of the genus; females also differ from those of all the other species, except M. australis , by the shorter and thicker tarsi and metatarsi I; they can also be distinguished from all other Mediothele by the much more elongated spermathecae and rounded sternum.

Female (Holotype). Total body length 4.92; cephalothorax elongate, of length 1.56, width 1.08; pars cephalica length 0.96, width 0.96. ALE largest, both eye rows recurved, with 6 thick setae before, and 4 thick setae behind ocular group. Fovea straight; dorsal midline of cephalothorax with series of 8 setae reaching fovea. Chelicerae with rastellum-like thick setae on anterior edge; with 6 large promarginal teeth and 10 denticles in basal part of fang furrow. Palpal coxae with 4–8 cuspules. Labium length 0.16, width 0.36, with 2 cuspules (other females with 1–3). Sternum wide, subcircular, 0.88 long, 0.92 wide, with three pairs of small marginal sigilla. Opisthosoma elongate, length 2.52, light brown, with lighter transverse bands forming chevron interrupted centrally. PLS with basal: medial: apical articles of lengths 0.36: 0.24: 0.12; PMS monoarticulate, length 0.28; ALS biarticulate, basal article 0.12 long, apical article very small, domed, of length 0.08, with 3–4 spigots. Tarsi I short, length 0.32, width 0.16; Metatarsi I 0.44 long. Chaetotaxy: All femora with series of dorsal setae along midline. Patellae: I, 0; II, 1 p a; III, 1–1 P, 1–2 D plus long basal dorsal seta, 7 P to D (from middle to edge); IV, 0–1–1 P; palp, 0. Tibiae: I, several long v and d setae; II, 1–1– 1 v post (long and thin), 2 v a ant; III, 2 V A ANT, 2–2 P, 2–2 D, 1 R, with many r and d small and thickened setae; IV, 0–1– 2 V A, 1 V A POST, 1 D B, 1 R ANT, 1–1–0 P; palp, 3 d a, 1–0–1–1 P, 1 V ANT, 2 V POST. Metatarsi: I, 1 V ANT, 1–1–0 V, 0–0–1– 1 V POST, with apical preening comb (of 2 bristles); II, 1 P MED, 1 V A ANT, 1 V B, 0–1–1– 2 V POST; III, 0–1–1–1–1 R, 1–1–1–1 P, 0–1– 1 V ANT, 1 V A, with 2 apical preening combs (of 4 bristles each); IV, 1–1–0–1 D, 1–1–0–1 P, 1–1– 1 V ANT, 1 V A, with 2 apical preening combs (of 5–3 bristles). Tarsi: I–IV, 0; palp, 0–1–1–1 P, 0–1–1–1 R. Trichobothria: all tarsi with 3; metatarsi I–III with 3, IV with 4; tibiae with 2 rows of 3.

Male. Unknown.

Distribution and habitat. Known only from the type locality. The specimens were found in small burrows in a small forested gully.

Other specimens examined. Chile: Región V (Valparaiso): Valparaiso: Casablanca [33°19'14"S 71°24'25"W], 8 Jan 1984 (P. Goloboff) 12 Ƥ ( MACN).

Figures

FIGURES 33 – 38. Mediothele minima sp. nov., female. 33 – 34. Right leg I, retrolateral and ventral views. 35. Sternum and maxillae. 36 – 37. Spinnerets. 38. Spermathecae.