Actinopus ariasi, Ríos-Tamayo & Goloboff, 2018

Ríos-Tamayo, D. & Goloboff, P. A., 2018, Taxonomic Revision And Morphology Of The Trapdoor Spider Genus Actinopus (Mygalomorphae: Actinopodidae) In Argentina, Bulletin of the American Museum of Natural History 2018 (419), pp. 1-84 : 31-32

Actinopus ariasi , sp. nov.

Figures 12A–G, 44

TYPE MATERIAL: HOLOTYPE ♂ (MACN-Ar 36628): Formosa: Reserva “El Bagual” [26º10′ S 58º56′ W], Nov. 2001 – Feb. 2002, G. Scrocchi, 1♂. PARATYPE: 1♂, same data ( FML- ARAN 02187).

ETYMOLOGY: The species is named in honor of Joan Salvador Arias, for his assistance to the senior author (D.R.-T.) during his Ph.D studies.

DIAGNOSIS: Males of A. ariasi can be characterized by a copulatory bulb with thin embolus (fig. 12D–F), BTA and ATA developed, Ak not extending to the apex. Few retrolateral spines on tibia II (fig. 12C), similar to A. magnus and A. cordobensis (from which it differs by presenting a wider ATA).

Female: Unknown.

DESCRIPTION: Holotype male (MACN-Ar 36628, fig. 12A–G): Total length: 12.00. Carapace (fig. 12A): length 3.72, width 3.60. Cephalic region: length 2.04, width 2.76; clypeus small with 16 bristles and 1 large central one; 5–6 bristles between PME and 3–4 behind each PME-PLE; 6 bristles on each side of the OQ, with central larger one. Fovea: length 0.54, width 1.08. Eyes, diameters and interdistances: AME 0.12 (small), ALE 0.24, PME 0.16, PLE 0.16; OQ width 0.72, anterior length 1.80, posterior length 1.60; AME-ALE 0.52, PME-PLE 0.08, AME-PME 0.32, ALE-PLE 0.40, AME- AME 0.16. Chelicerae: Length 1.80, width 0.90, shallow internal ridges on 1:2 A. Cheliceral apex with 8 recumbent and elongated bristles that cover the base of the fang. Cheliceral prolongation without cusps; furrow with 8 large promarginal teeth and 5 retromarginal (small ones between 2nd-3d and 3d-4th) and 7 denticles, near the promarginal teeth. Labium: length 0.88, width 0.76. Maxillae: superior length 1.00, inferior length 1.68, width 1.32. Sternum (fig. 12G): Center flat; length 2.76, maximum width 2.36, minimum width 1.36. Postlabial sigillum deep, posterior sigilla well defined and shallow. Abdomen: Length 4.80, with dark bristles and 3 spiniform dorsal bristles. PMS: length 0.40; PLS: length of basal:medial:apical segments 0.52:0.32:0.04. Spigots: 1 large, 30 small on PMS; PLS, numbers of large(small) spigots on basal:medial:apical article 3(40):3(46):1(55). Lengths of legs and palp: I: 3.84, 1.50, 2.40, 2.88, 1.98, 12.60. II: 3.60, 1.50, 2.40, 3.00, 1.98, 12.48. III: 3.00, 1.38, 1.92, 3.24, 2.10, 11.64. IV: 3.90, 1.80, 3.54, 3.48, 2.28, 15.00. Palp: 3.72, 1.68, 3.42, –, 1.08, 9.90.

Chaetotaxy: Right tarsus III missing, only left described. Femora: 0. Patellae: I-II, 0; III, 15 P SUP-D ANT, 1 P A +9 on the margin, 1-1-1 D, 6 R A +7 on the margin; IV, 41 P SUP-D ANT, 1 P A. Tibiae: I, 1-1-2-3 V; II, 1-1-1-1-0-2 R INF, 1-2-1-4 V; III, 2-2-1-1 P, 2-1-3 R (1:2 A), 1-1-2 V, with an apical crown of 18 thorns; IV, 1-3-2-5 V. Metatarsi: I, 1-1-1- 1-1-1 P INF, 2-2-2-2-2-1-1-2 R INF-V POST, 1-2-1 V (1:2 B); II, 1-1-1-2-1-2-1-3-2-2-4 R INF-V POST, 1-1-1-1-1-1 V ANT (1:2 A), 1-1-1 V (1:2 A); III, 1-1-1-2-1-2-1-2 P, 1-1-0-1 D ANT (3:4 B), 1-2-1-3-1-1-1-3 on row D POST-R, 1-1-1-2-2-2-1-3 V; IV, 2-1-2-2-1-1-1 P INF, 1 D A ANT, 1-2-1-1-2-2-2-1-5 V. Tarsi: I, 1-1-1-1-1 P INF, 1-1-2-1-1-3-1-2-6 R INF, 1 V M; II, 1-1-1-1-1-1-2-1-2 P INF, 1-1-1-2-1-5- 1-4-4 R INF, 1-0-0-1 V; III, 1-1-1-1-0-1-2-1-1- 2-2 P INF, 1-3-2-2-5-5-2 R INF; IV, 1-1-2-3-4-6-4-2 P INF, 1-3-1-2-1-1-1-2-1-2-1 R INF. Total number of retrolateral spines on tibiae I and II (fig. 12C): 0 and 6 respectively. Palp: Tibia short and thickened (width/length: 0.35±0.01) (fig. 12B). Bulb (fig. 12D–F) with ATA and BTA well developed embolus with a series of denticles at the base. Pseudoscopula: Tarsi: I sparse (1:2 A); II sparse (3:4 A); III-IV, dense and uniform. Metatarsi: without pseudoscopula. Trichobothria: Tibiae: I-II 4-6; III- IV 6-6. Metatarsi: I-II 10; III 9; IV 8. Tarsi: I 8; II-III 9; IV 7. Color: Carapace dark reddish brown cephalothorax, cephalic region and chelicerae darker. Fovea almost black. Abdomen dark brown, booklungs with dark markings. Spinnerets yellowish. Legs like carapace with tarsi-metatarsi lighter; palp tibiae light.

DISTRIBUTION: Only known from the type locality.

OTHER MATERIAL EXAMINED: Formosa: Same data and collector as holotype, 83 ♂♂ (FML- ARAN 02188).