Birabenella argentina ( Birabén, 1955 ) 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 : 11-14

Birabenella argentina ( Birabén, 1955) , new combination

Figures 36–50 , 69

Oonopinus argentinus Birabén, 1955: 73 , figs. 1–4; male holotype from Argentina: Catamarca Province: Mutquín (road from Andalgalá to Pomán) ca. 28°18′ S, 66°8′ W, in MLP 280 (PBI_OON 14757): examined. Brignoli 1978: 20.

REMARKS: The vial with the type specimen is labeled as “ Oonopinus rupicola, Birabén / Holotypus.” Ramírez determined as O. argentinus probable male holotype (note in vial); see also Pereira et al. (1999). Although the specimen does not have the number assigned by Birabén in his private collection, I assume that this specimen is the holotype because all the data of the label match with those of the publication (especially the locality and date), and it seems to be the specimen illustrated.

OTHER MATERIAL EXAMINED: Argentina: Catamarca: Hualfin ; M. Birabén col., no date, 1 male ( MLP 14599, PBI _ OON 14758) ca. 27°13′S, 66°49′ W.

DIAGNOSIS: The male is very similar to that of B. homonota , but clearly differs in the lack of leg spines, the dorsal bulge on the palpal bulb, and the small dorsal scutum on the abdomen (figs. 36, 49–50). The palpal tibia is unmodified and the membranous elements in the apical bulb are different (figs. 49–50).

DESCRIPTION: Male (holotype, in poor condition): Total length 1.71. CEPHALOTHORAX: Carapace orange-brown; nonmarginal pars cephalica setae absent (probably lost); nonmarginal pars thoracica setae light (probably by the condition of preservation). Clypeus setae light, stout. Eyes mostly as in B. homonota ; all subequal, circular. Sternum without radial furrows between coxae I–II, II–III, III–IV, lateral margins unmodified. Mouthparts: setae light. Labium subpentagonal, elongated; without setae. Endites converging anteriorly, tip with one strong, spinelike projection (fig. 47). ABDOMEN: dorsal scutum absent. Dorsum setae light. Epigastric and postepigastric area setae light. LEGS: orange; patella plus tibia I near as long as carapace. Leg spines absent. Tarsi I to IV superior claws unipectinate. Trichobothria not examined. GENI-

TALIA: Palpal embolus difficult to see, surrounded by several membranous elements, all arising from a broad opening of the bulb, which has a distinct, small, digitiform ventral apophysis.

VARIABILITY: The original description mentioned that the eyes are on a dark pigmented area. In the holotype seems to be faded, but in the other known male the dark area is still visible (fig. 45).

Female: Unknown.

NATURAL HISTORY: The original description ( Birabén, 1955: 74) mentioned only that the holotype was found under a stone.

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 36–44. Birabenella argentina (Birabén); 36–43, male holotype (PBI_OON 14757); 44, male (PBI_ OON 14758). 36–37, habitus; 38, abdomen; 39–43, cephalothorax; 44, right tarsus IV. 36, 39, dorsal; 37, 43, lateral; 38, 40, ventral; 41, posteroventral; 42, anterior; 44, prolateral.

FIGURES 45–50. Birabenella argentina (Birabén), male (PBI_OON 14758). 45–48, cephalothorax; 49–50, left palp, prolateral. 45, dorsal; 46, ventral; 47, lateral; 48, anterior; black arrow: ventral digitiform projection of the bulb, white arrow: spinelike projection on the endites; E = embolus.