Carajas, Brescovit, Antonio D. & Sanchez-Ruiz, Alexander, 2016

Brescovit, Antonio D. & Sanchez-Ruiz, Alexander, 2016, Descriptions of two new genera of the spider family Caponiidae (Arachnida, Araneae) and an update of Tisentnops and Taintnops from Brazil and Chile, ZooKeys 622, pp. 47-84 : 64-65

Taxon classification Animalia Araneae Caponiidae

Carajas gen. n.

Type species.

Carajas paraua sp. n.

Etymology.

The generic name is an apposition to the type locality where all known specimens were collected and is masculine in gender.

Diagnosis.

Members of Carajas gen. n. can be easily separated from other caponiid genera by having anteriorly and posteriorly strongly projected endites (Figs 13J, 14D), a very short cheliceral fang (Fig. 15 D–E), absence of unpaired claws on all legs, and the posterior paired claws with distal tip thickened and covered with dense and short bristles (Fig. 14G, 15H).

Description.

Moderate-sized caponiids (Fig. 13A, I). Carapace oval, anteriorly narrowed to less than half of its maximum width, pars cephalica rounded, pars thoracica flat medially and sloping posteriorly; cuticle of carapace smooth, covered with short and uniform setae; clypeus almost smooth; thoracic groove inconspicuous, almost obsolete (Fig. 13A, I). Eyes absent (Figs 13A, I; 14A, 15A). Cheliceral paturon with long, weak bristles, mainly on frontal area; base of fang unmodified; fang short with large opening, median lamina short, occupying a small space by the white membranous lobe; lateral surface with small sulci of stridulatory ridges (Fig. 14C), pick small on prolateral basal side of palpal femur (Fig. 16A). Endites convergent, strongly projected, extending anteriorly far beyond the anterior margin of the labium, and posteriorly widened, extending far beyond the posterior margin of the labium (Figs 13J, 14D), covered with many small and long setae (Fig. 14 D–E), with strong distal serrula consisting of a single tooth row. Labium triangular, strongly fused to sternum, not invaginated at base, covered with a few scattered setae, distal area hyaline (Figs 13B, 14E); labrum elongate, narrow, subtriangular, distally slightly elevated. Sternum longer that wide, without radial furrows between coxae, covered with small and uniform setae, not fused to carapace, with sclerotized lateral and posterior borders (Figs 13B, J; 14B); cephalothoracic membranes without epimeric sclerites, but short triangular sclerites extend from the sternum between coxae of endites and coxa I, I and II, II and III, and III and IV, shorter triangles extend to each coxae, straighter on coxae III and IV, posterior border triangular between coxae IV (Fig. 13B, J). Legs formula 4213, without spines, metatarsi and tarsi entire, without subsegmentation or membranous processes, tarsi with two claws, lack unpaired claws, surrounded with elongate hairs; paired claws I-II with approximately six teeth, distal tip of claw elongate (Fig. 15G), III-IV weakly curved, with 3-4 short and well-separated teeth, distal tip of claw thickened, covered with dense and short bristles (Figs 14G, 15H). Tibiae, metatarsi, and tarsi with trichobothria in a single row, bothrium ridged (Fig. 14I), and very long bristles, several of them longer than metatrsus (Figs 13 C–D, 14H); tarsal organ oval, exposed, with concentric ridges and two distal receptors (Fig. 15I); female palpal tarsus three times longer than the tibia, prolateral surface densely covered with setae, without claw (Figs 13 G–H, 15 B–C). Abdomen without scutum; covered uniformly with short setae, not striated (Fig. 13 A–B, H–I). Epigastric region slightly protruding, with two pairs of respiratory spiracles, connected to large tracheal trunks directed anteriorly (Fig. 16D), posterior spiracles connected by rebordered groove extending parallel with the anterior spiracles; postepigastric scutum not fused to epigastric scutum. Males and females with six spinnerets in typical caponiid arrangement, anterior laterals with single, presumably major ampullate gland spigot, posterior medians with large, flattened minor ampullate gland spigot and posterior laterals with approximately ten aciniform gland spigots. Male palpal patella and tibia shorter that femur, unmodified; cymbium ovoid, elongate, prolateral surface densely covered with strong setae; bulb globose; embolus short, ribbon-like at base, slightly curved distally, tip enlarged and rounded (Figs 13 E–F, 14 J–L, 16 A–C). External female genitalia with postepigastric scutum represented only by a basal sclerotized band and part of receptaculum visible through transparent area (Fig. 13K). Internal female genitalia with a membranous anteromedian receptaculum formed by a short unsclerotized median duct with a wide base leading to a large, globose sac. This sac is associated with elongate, sclerotized transverse bars with a dorsally projected anterior margin (Figs 15 J–L, 16D).

Distribution.

Known only from caves in Carajás region, in the state of Pará, Brazil.