Types. Holotype ♂ from 5km north of Villavieja ( 3°13′48.72″N; 75°10′44.26″W), Desierto de La Tatacoa, Huila, Colombia, 436m, VI.2016, A. Porta leg. (ICN-Ar-12266). Paratypes: two ♂ and two ♀, same data as holotype (ICN- Ar-12267 [ 1♀]; ICN-Ar-12268 [ 1♂]; ICN-Ar-12269 [ 1♂, 1♀]); one ♂ and ♀ same data as holotype (IBSP 246896); ♂ and ♀ same as holotype (MACN-Ar-41718 [ 1♂]; MACN-Ar-41747 [ 1♀]).
Etymology. The specific epithet is referent to the type locality where the species was found, La Tatacoa desert. The name is a noun in apposition.
Diagnosis. Males of Tetrablemma tatacoa sp. nov. resemble those of T. thamin Labarque & Grismado, 2009 and T. mochima sp. nov. by the presence of a process separated at the base of the embolus and an embolic process (see Labarque & Grismado, 2009:56, figs 1, 3; Fig. 6 D−E). Males of Tetrablemma tatacoa sp. nov. can be distin- guished from those of the other two species by having a unique process on the base of the embolus, which is 3/4 as long as the embolus (bifid in T. thamin, with branches of different lengths; whole but wider and shorter in T. mochima sp. nov.); a short embolic process almost 1/2 as long as the embolus (very reduced in T. thamin; absent or very small and subapically placed in T. mochima sp. nov.); and a long embolus, slightly curved at the anterior side ( Figs 2 A−B, 4C−D). Females can be diagnosed by having an epigynum with very large and spherical seminal receptacles, a central process almost as long as the inner vulval plate, and thin lateral horns ( Fig. 2 C−E).
Description. Male ( Holotype, ICN-Ar-12266). Total body length 1.11, carapace length 0.41, width 0.39, height 0.37. Clypeus height 0.21. Eye diameters and interdistances: ALE 0.05, PLE 0.03; PLE separated by approximately one diameter. Sternum length 0.29, width 0.28. Chelicerae (paturon) length 0.14. Legs: Leg I—femur 0.37/ patella 0.11/ tibia 0.27/ metatarsus 0.19/ tarsus 0.20/ total 1.14; II—0.32/ 0.09/ 0.23/ 0.17/ 0.18/ 0.99; III—0.29/ 0.08/ 0.19/ 0.15/ 0.16/ 0.87; IV—0.37/ 0.11/ 0.27/ 0.18/ 0.15/ 1.08. Abdomen length 0.70, width 0.53. Body coloration reddishbrown ( Fig. 1 A−C). Legs yellow-brown. Spinnerets yellow. Carapace: cephalothorax finely reticulated, slightly raised and suboval-shaped; four eyes in one group on a low tubercle at the posterior half of carapace, white with black ocular base, ALE>PLE, ALE and PLE adjacent; clypeus high and anteriorly projected with the anterior edge rounded ( Fig. 1A); thoracic region reticulated and with radial grooves ( Figs 1A, 3A); Chelicerae with a wide and developed frontal apophysis on the anterior side and with wide and laminar basal projections ( Fig. 3 A−B); endites subquadrangular-shaped with a very wide basal edge and narrowing toward the distal edge; labium trapezoidalshaped and wider than long; sternum rugose and longer than wide ( Fig. 1C). Leg cuticle striated and covered with modified setae mainly on metatarsus and tarsus ( Fig. 4 E−F); tarsal claw very small and pectinated, with 7−8 teeth ( Fig. 4F). Opisthosoma: covered with black and fine setae on posterior edge ( Fig. 1A); dorsal scutum oval-shaped and smooth; ventral scutum (pulmonar scutum) finely reticulated and with some fine setae around the epyadrium ( Figs 3C, 4 A−B); lateral scutum I very long, extending to the posterior side of the anal plate ( Fig. 1B); postgenital scutum trapezoidal-shaped, long and narrow, with the anterior edge straight, and lateral edges with quadrangular apex; preanal scutum rectangular-shaped and approximately twice as wide as postgenital scutum, with all edges rounded. Six spinnerets surrounded by the anal plate ( Fig. 3D), ALS large with two articles, basal article very wide, distal article short and covered by piriform gland spigots; PMS very short with two articles, with one relatively large spigot, presumably from a minor ampullate gland; PLS also with two articles, apical article flat and covered by long modified setae and long, presumably actiniform gland spigots ( Fig. 3D). Palp: femur cylindric with some simple setae on the cuticle; patella short with long setae; tibia short and very swollen with simple and long setae; cymbium short with black and long setae and a small organ; bulb large and pear-shaped; spermatic ducts very wide at the base and narrowing toward the embolus; embolus long, straight, and inserted basally, filiform toward distal end with a short and sharp embolic process; process of the embolic base approximately 3/4 as long as the embolus ( Figs 2 A−B, 4C−D).
Female ( Paratype, ICN-Ar-12267). Total body length 1.13, carapace length 0.41, width 0.40, height 0.27. Clypeus height 0.13. Eye diameters and interdistances: ALE 0.05, PLE 0.04; PLE separated by one diameter. Sternum length 0.28, width 0.27. Chelicerae (paturon) length 0.13. Leg measurements: Leg I—femur 0.27/ patella 0.09/ tibia 0.19/ metatarsus 0.16/ tarsus 0.12/ total 0.83; II—0.24/ 0.09/ 0.16/ 0.16/ 0.14/ 0.79; III—0.26/ 0.10/ 0.18/ 0.16/ 0.16/ 0.86; IV—0.36/ 0.11/ 0.31/ 0.22/ 0.13/ 1.13. Abdomen length 0.72, width 0.58. Coloration as male ( Fig. 1 D−F). Carapace: cephalothorax finely reticulated slightly raised and subtriangular-shaped; eyes white, ALE>PLE i n size; clypeus high and anteriorly projected ( Fig.1D); thoracic region granulated and with radial grooves ( Fig. 5A); Chelicerae with wide and a slightly developed apophysis on the proximal side ( Fig. 5B); endites subquadrangular-shaped with a wide basal edge, narrowing toward the distal edge ( Fig. 5D); labium trapezoidal-shaped and wider than long ( Fig. 5 C−D); sternum rugose with few setae on lateral edges ( Fig. 5 C−D). Leg cuticle striated ( Fig. 1 D−F). Opisthosoma: covered with white and black fine setae, mainly on posterior edge ( Fig. 1D); dorsal scutum oval-shaped and smooth; ventral scutum (pulmonar scutum) covered with short and fine setae ( Fig. 5E); lateral scutum long, extending to half of the anal plate ( Fig. 1B); postgenital scutum subrectangular-shaped, long, and narrow ( Fig. 5E); preanal scutum rectangular-shaped and wide, with rounded borders ( Fig. 5E). Epigynum: orifice small and situated on posterior edge of epigynal fold; inner epigynal plate long and straight; central process short; seminal receptacles large, membranous, and bean-shaped; vulval ducts long and thin ( Fig. 2 C−E).
Variation. Males (n=6): total length: 1.00–1.06; carapace length: 0.47–0.52. Females (n=6): total length: 1.02– 1.17; carapace length: 0.41–0.51.
Habitat. The specimens were collected using Berlese-Tullgren traps from leaf litter and between shrubs and plants of the family Cactaceae, in a tropical dry forest (following the classification proposed by Etter et al., [2008]), within a regenerated fragment in the Huila department.
Distribution. Only known from its type locality ( Fig. 7).