Birabenella pizarroi, Grismado, 2010

Grismado, Cristian J., 2010, Description of Birabenella, a New Genus of Goblin Spiders from Argentina and Chile (Araneae: Oonopidae), American Museum Novitates 2010 (3693), pp. 1-24 : 14-16

Birabenella pizarroi , new species

Figures 2 , 10–14 , 51–59 , 69

TYPE MATERIAL: Female holotype from Chile: Coquimbo Region: Choapa Province: Los Vilos , near Quebrada de Quereo ; 31°55′ 35.4″S; 71°30′ 51.1″W ( WGS84 ) ; alt. 19 m ( GPS) ; 19.VIII.2009; coll. C. Grismado, A. Ojanguren, J. Pizarro and F. Alfaro. Under stones. Deposited in MHNS ( PBI _ OON 14992) .

OTHER MATERIAL EXAMINED: None.

ETYMOLOGY: The specific epithet is a patronym in honor of Jaime Pizarro-Araya (Universidad de La Serena), co-collector of the Chilean specimens described in this contribution, and in recognition of his hospitality and help during my Chilean fieldwork.

DIAGNOSIS: This species resembles B. elqui in having a smooth to finely reticulate carapace, smooth sternum and spineless legs, but differs in the W-shaped internal duct of the posterior receptaculum, and by the less sinuous anterior part of the internal female genitalia (fig. 59).

DESCRIPTION: Female (holotype): Total length 1.64. CEPHALOTHORAX: Carapace orange, surface of elevated portion of pars cephalica smooth, sides finely reticulate. Clypeus high, ALE separated from edge of carapace by their radius or more. Eyes: three diads on black pigment, ALE largest; ALE-PLE separated by less than ALE radius. Sternum orange, without radial furrows between coxae I–II, II–III, III–IV, surface smooth, microsculpture absent, lateral margins unmodified. Mouthparts: chelicerae anterior face with basal swelling. Labium anterior margin not indented at middle, subpentagonal. Endites orange, strongly convergent. Palpal spines absent, with enlarged setae on tarsus. ABDOMEN: dorsum soft portions pale orange. Dorsal scutum absent. LEGS: orange. Leg spines absent. Tarsi I to IV superior claws unipectinate. Trichobothria (only tibial and metatarsal examined with SEM): base rounded, internal texture of the aperture not gratelike, hood covered by low, closely spaced ridges, hood and distal plates well differentiated. Tarsal organ with 3 sensilla visible on leg I (one of them shallow), capsulate, opening intermediate between oval and a long slit. GENITALIA: shape: anterior diverticle thickened, the posterior receptaculum with anterior wall strongly sclerotized and anteriorly concave, and with an internal W-shaped duct (fig. 59).

Male: Unknown.

NATURAL HISTORY: The only known specimen was collected under a stone in disturbed coastal grasslands near Quebrada de Quereo, Los Vilos (fig. 2). The type locality belongs to the shrubland steppe subregion, with the main plant formations of the region corresponding to the “arborescent shrubby steppe,” as described in Gajardo (1993).

Figures

FIGURE 69. North-central Chile and northwestern Argentina, showing the geographic distribution of Birabenella species: B. argentina (squares); B. homonota and B. elqui (triangle) and B. pizarroi (circle).

FIGURES 1–2. Habitats of Birabenella species in Coquimbo, Chile. 1, Cuesta Porotitos, the type locality of B. homonota, n. sp., and B. elqui, n. sp. 2, disturbed grassland Near Quebrada del Quereo, Los Vilos, type locality of B. pizarroi, n. sp.

FIGURES 10–14. Birabenella pizarroi, n. sp., female holotype (PBI_OON 14992), morphology of left leg I. 10, tarsus, apicodorsal; 11, tarsal claws and claw tufts, apical; 12, metatarsus, dorsal; 13, metatarsal trichobothria, dorsal; 14, tarsal organ, dorsal.

FIGURES 51–59. Birabenella pizarroi, n. sp., female holotype (PBI_OON 14992). 51–53, 57, habitus; 54–55, cephalothorax; 56, abdomen; 58, epigastric area; 59, internal genitalia, cleared. 51, 54, 59, dorsal; 52, 55–56, 58, ventral; 53, lateral; 57, anterior. PR= posterior receptaculum.