Birabenella Grismado, 2010

Piacentini, Luis N., Grismado, Cristian J. & Ramírez, Martín J., 2017, An Update of the Goblin Spider Genus Birabenella Grismado, 2010 (Araneae: Oonopidae), with the Description of Three New Species, American Museum Novitates 2017 (3883), pp. 1-20 : 5-7

Birabenella Grismado, 2010

Birabenella Grismado, 2010: 3 ;

type species B. homonota Grismado, 2010 .

DIAGNOSIS: Soft-bodied oonopines with unipectinate tarsal claws in both sexes (figs. 2 C–E, 3F; Grismado 2010: figs. 6, 7–8, 10–11). Males with conspicuous ventral digitiform projection on the male palpal bulb (figs. 3A–E, 10 A, C, E; Grismado 2010: figs. 33, 49). Female genitalia with strongly thickened anterior or anterodorsal wall of the posterior receptacle (figs. 10 B, D, F; Grismado, 2010: figs. 35, 59, 68).

DESCRIPTION: See Grismado (2010). Additional data are provided below. Carapace and sternum texture reticulate to smooth; setae on the dorsum of the abdomen usually stout and flattened, but needlelike in the smaller species. Endites of males with apical, dark, spinelike setae. Legs: Tarsal claws unipectinate in all species, macrosetae present only in the type species ( B. homonota ); tarsal organs partially examined, showing variability in shape and probably also in number of receptors: on tarsal organ I of B. homonota and B. pizarroi the aperture is rela- tively narrow, all other features as in other oonopines (a ridge on proximal margin, three receptors, one large and two small, transversely arranged, see fig. 1A, B); in B. kamanchaca and B. chincha , aperture wider, proximal ridge less conspicuous; only one clearly visible receptor (apparently homologous to the large, unpaired receptor of B. homonota and B. pizarroi ); in B. chincha , no trace of other sensilla (fig. 1D); in B. kamanchaca , data are inconclusive for interpreting presence of tiny projections (fig. 1C). Tarsal organ II of B. kamanchaca with similar pattern of receptors as that of leg I, but opening narrower (fig. 1E). Tarsal organ of male palp of B. chincha and third leg of B. kamanchaca similar to those of most oonopines (fig. 1G, F, respectively). Genitalia: Copulatory bulb of all known males with distinctive ventral, sometimes curved, digitiform projection (fig. 10A, C, E; Grismado, 2010: figs. 31–33, 49–50); sperm duct weakly sclerotized (as in Oonopinae), with longitudinal tendon running parallel to most of its length; terminal part of bulb with oval opening (like an alveolus) from where several flattened projections of variable shapes arise, surrounding the embolus opening (fig. 3A–E). Female internal genitalia: anterior element of variable shape, always with lumen, separated from posterior part of genitalia by apparently small, thin transverse bars, probably functioning as locking structures; posterior elements consist of copulatory duct of diverse shape (usually sinuous or coiled, with thick walls), a transverse set of sclerotized elements associated to muscle insertions, posterior receptacle with thickened anterior to anterodorsal wall, with apparently wrinkled or reticulated texture under light microscopy; internal tubes of diverse shape and course in the area of the posterior receptacle (fig. 10B, D, F).

DISTRIBUTION: From southern Peru (Ica department) to Coquimbo region in Chile and Jujuy and Catamarca Province in Argentina (although no records are yet known from Bolivia). In Chile all species were collected near the coast, in arid or semiarid habitats; in Argentina, the records also include xerophytic biomes.