Actinopus argenteus, 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 : 26-31

Actinopus argenteus , sp. nov.

Figures 10A–I, 11A–D, 44

TYPE MATERIAL: HOLOTYPE ♂ (MACN-Ar 31204): Córdoba. Reserva Natural Chancaní [31°20′ S 65°27′ W], 15–30 Jan. 2004, M. Izquierdo, 1♂. PARATYPES: ♀ ♂ (different vials) (MACN-Ar 36575, 36576 respectively). Santiago del Estero. Colonia Dora [28°35′ S 62°56′ W], 7–8 Feb. 1985, C. Szumik and P. Goloboff. Córdoba:

Same data as the male holotype, Mar. 1992, P. Goloboff and C. Szumik, 1♀ (MACN-Ar 27118). ETYMOLOGY: The specific name, argenteus , is a Latin adjective meaning “silvery,” in reference

to the silver-grey coloration of the male abdominal dorsum.

DIAGNOSIS: Females of A. argenteus can be distinguished by the narrow sternum (fig. 11D), the spermathecae (fig. 11C) basally wide, with truncated fundus, with the apical margin concave and external lobes projected perpendicular to the duct. Differs from A. gerschiapelliarum and A. casuhati by their larger size and the absence of thorns distal to the crown of thorns on tibia III. Males can be recognized by the silvery-gray color of the abdominal dorsum (fig. 10D), similar to A. pampa , from which it is distinguished by the absence of a ventral concavity in the copulatory bulb and small ATA. Differs from A. pampa by the larger number of retrolateral thorns on tibiae II (fig. 10F).

DESCRIPTION: Holotype male (MACN-Ar 31204, figs. 10A–I): Total length: 14.64. Carapace (fig. 10A): length 5.88, width 5.52. Cephalic region: length 3.96, width 4.14; clypeus short with 5 small bristles between AME-ALE, 14 between PME and 3–4 bristles behind each PME-PLE dyad, 5 bristles on both sides of the OQ. Fovea: length 1.02, width 2.4. Eyes, diameters and interdistances: AME 0.32 (large), ALE 0.36, PME 0.24, PLE 0.24, OQ length 1.04, anterior width 3.08, 2.76 posterior width; AME-ALE 0.8, PME-PLE 0.12, AME-PME 0.48, ALE-PLE 0.56, AME-AME 0.24. Chelicerae: length 3.36, width 1.80, anterior dorsal half with slight transverse grooves; cheliceral apex with 12 recumbent and elongated bristles that cover the base of the fang. Cheliceral prolongation without cusps; furrow with 6 large promarginal teeth, 6 retromarginal, and 17 denticles near the promarginal teeth. Labium: length 1.26, width 1.26. Maxillae: anterior length 1.80, posterior length 2.28, width 1.62. Sternum (fig. 10C): Slightly depressed centrally; length 3.66, maximum width 3.06, minimum width 1.32. Postlabial sigillum shallow, posteriorly reaching the middle of the sternum; posterior sigilla well defined and shallow. Abdomen (fig. 10B, D): Length 5.52, with scarce and small bristles, thicker in the dorsum. PMS: length 0.56; PLS: length of basal:medial:apical segments 0.84:0.36:0.28. Spigots: 2 large, 14 small on PMS; PLS, numbers of large(small) spigots on basal:medial:apical article 3(12):4(21):2(34). Lengths of legs and palp: I: 5.70, 2.52, 3.12, 4.20, 2.40, 17.94. II: 5.46, 2.52, 3.24, 4.44, 2.40, 18.06. III: 4.50, 2.70, 2.52, 4.74, 2.70, 17.16. IV: 6.00, 2.88, 4.68, 5.16, 3.00, 21.72. Palp: 5.22, 2.64, 4.56, –, 1.50, 13.92.

Chaetotaxy: Palp: 0. All femora: 0. Patella: I-II, 0; III, 1-1-1-1-1-1 D, 40 P SUP +9 on the margin, 1-1 R +8 on the margin; IV, 69 P SUP-D ANT +4 near the edge. Tibiae: I, 2 R A, 1-1-1-1-2 V ANT, 1-1-1-2-1-2-1-2 V POST; II, 2-3-4-1-4-3-4 R, 1-1-1 V, 2 V A ANT, 1-1-1-1-1-3 V POST; III, 1-2 P, with a crown of 17 thorns, 2-1 R, 2-1-2 V A; IV, 1-2-3 P ANT, 2-1-1-1-2 V ANT, 2 V A POST. Metatarsi: I, 1-1-2 V, 1-1-1-2-3-2-2-3-2 V ANT, 3-1-4-2-2-1-3-1-2-2-1-4 V POST-R INF; II, 4-1- 3-3-2-1-1-2 V, 1-1-2-2-2-2-2 V ANT, 2-1-1-4-3-4- 4-5 V POST-R INF; III, 1-1-1-1-1-1 D POST, 2-1-1-1-1-1-1-1 D ANT, 1-1-2-1 V, 2-1-2-1-1-3-2 V ANT, 2-2-1-3-2-2-1-4-2-4 V POST-R INF; IV, 2-1-1-1-2-1 V, 1-1-1-1-2-4 V POST-R INF, 1-2-1- 2-3-4 V ANT-P INF. Tarsi: I, 2-1-1-1-1-1-1-1 P INF, 1-1-3-2-1-1-3-2-6 R INF, 1-1 V A; II, 2-2-1- 1-1-2-2-1-1 P INF, 2-2-1-1-2-4-5-7 R INF, 2 V A; III, 1-2-2-4-2-4-4 P INF, 1-1-3-3-4-1-2-1-1 R INF, 2-3-5 V ANT; IV, 2-3-1-3-3-4-2-2-3-3 P INF, 1-1- 1-1 2-8 R INF, 1-1-1-3 V. Total number of retrolateral spines on tibiae I and II (fig. 10F): 2 and 21 respectively. Palp: Tibia long and slender (width/ length: 0.28±0.02) (fig. 10E). Bulb (fig. 10G–I) rounded, embolus slender, ATA and BTA poorly developed. Pseudoscopula: Tarsi: I-II sparse (distributed throughout the segment, more abundant A); III-IV, dense and uniform. Metatarsi: I-II, without pseudoscopula; III-IV, scarce and apical. Trichobothria: Tibiae: I 4-6; II 5-7; III-IV 7-8. Metatarsi: I-II 10; III 9; IV 10. Tarsi: I 15; II-III 14; IV 12. Color: Carapace and chelicerae dark reddish brown. Abdomen light brown, dorsum silver grey; booklungs with dark markings. Legs like carapace, tarsi light; palp patella-tibia light.

Paratype female (MACN-Ar 36575, figs. 11A–D): Total length: 19.56. Carapace (fig. 11A): length 6.72, width 6.60, with 18 bristles on each posterior margin. Cephalic region: Length 3.84, width 5.70; clypeus with 60 bristles, chilum not visible, 7 bristles between AME-ALE (closer to ALE), 23 bristles between PME and 10–12 behind each PME-PLE dyad, 2 bristles central dorsal on line to the fovea; 13–15 small bristles on each side of the OQ. Fovea: length 0.60, width 1.14. Eyes, diameters and interdistances: AME 0.20, ALE 0.48, PME 0.24, PLE 0.28, AME-ALE 1.20, PME-PLE 0.24, AME-PME 0.72, ALE-PLE 0.68, AME-AME 0.32, OQ length 1.36, anterior width 3.92, 3.40 posterior width. Chelicerae: Length 3.90, width 2.58; cheliceral apex with 15 recumbent and elongated bristles covering the base of the fang. Rastellum with 12 blunt marginal cusps, and 10 smaller dorsal ones. Fang groove with 7 promarginal teeth and 5 retromarginal ones (1 small one between 2nd-3d, 3d-4th; and 4th- 5th) and 20 denticles in the furrow, near the promargin. Labium: length 1.80, width 1.32, with 31 anterior cuspules. Maxillae: anterior length 1.98, posterior length 2.52, width 1.98, with +110 cuspules 1:3 V ANT, extending to the anterior face. Sternum (fig. 11D): With a slight central depression; length 4.80, maximum width 3.90, minimum width 1.56. Postlabial sigillum shallow, posterior sigilla shallow and well defined. Abdomen: Length 7.80, globose, with dark bristles. PMS: length 0.88; PLS: length of basal:medial:apical segments 1.12:0.32:0.24. Spigots: 2 large, 25 small on PMS; PLS, numbers of large(small) spigots on basal:medial:apical article 4(28):4(36):3(50). Lengths of legs and palp: I: 4.20, 2.70, 1.92, 2.40, 1.20, 12.42. II: 4.20, 2.58, 1.92, 2.58, 1.20, 12.48. III: 3.90, 3.00, 1.50, 2.88, 1.20, 12.48. IV: 4.80, 3.18, 2.70, 3.00, 1.02, 14.70. Palp: 3.90, 2.40, 2.70, –, 2.70, 11.70.

Chaetotaxy: Metatarsi and tarsi missing on the right leg III, only the left are described. All femora: 0. Patellae: I-II, 0; III, 7 R A, +12 on the margin, 2-6 P (1:2 A) +11 on the margin; IV, 53 P SUP-D ANT +4 on the edge; palp, 1-1-1- 1 P. Tibiae: I, 1-1-2 P (1:2 A), 26 R INF, 1-1 V POST ; II, ~90 R INF, 1-1-1 V POST; III, 1 D B, with a

crown of 20 thorns, 33 R (3:4 A); IV, 0; palp, 16 P INF23 R INF. Metatarsi: I, 3-2-3-2-1-2-2-1-2-3 P INF, 24 R INF, 1-1/1-1-2 V POST; II, 1-1-2-1-3- 1-3 P INF, 26 R INF, 1-1-2 V POST; III, 1-2-1-2- 1-2 D ANT, 46 row D POST-R (more abundant R A), 1 V A POST; IV, 1-1-1-2-4 P, 2 V A. Tarsi: I, 2-1-2-1-1-1-1 P INF, 22 R INF, 1-2 V (1:2 A); II, 2-1-2-1-2-1-3-1-1 P INF, 2-1-3-3-3-1 R INF, 1-1- 1-2 V; III, 23 R, 40 V-P; IV, 29 V-P; palp, 19 P, 24 R, 2 V A. Total number of retrolateral spines on tibiae I and II (fig. 11B): 26 and 90 respectively. Trichobothria: Tibiae: I 4-4; II 5-6; III 7-5; IV 8-6. Metatarsi: I 12; II 18; III 12; IV 10. Tarsi: I 11; II 16; III 10; IV 8. Color: Carapace reddish brown; cephalic region dark with a triangular light spot on ocular area. Abdomen brown, booklungs with

dark markings. Spinnerets yellowish brown; labium and maxillae darker. Legs reddish brown.

DISTRIBUTION: Provinces of Santiago del Estero, Córdoba, and Catamarca.

OTHER MATERIAL EXAMINED: Santiago del Estero. Colonia Dora [28°35′ S 62°56′ W], Jan. 1985, C. Szumik and P. Goloboff, 3♀, 3 immature (MACN-Ar 36577). Same data, 7–8 Feb. 1985, C. Szumik and P. Goloboff, 3 immature (MACN-Ar 36578). Córdoba. Reserva Natural Chancaní [31°20′ S 65°27′ W], 6 Apr. 1987, P. Goloboff, 3 immature (MACN-Ar 36579). Catamarca. 10 km al Sur de Recreo [29°16′ S 65°04′ W], 9 Jan. 1998, P. Goloboff, 1♀ (MACN-Ar 36580). Singuil, El Chorro, 20–31 Jan. 1953, W. Patridge and S. Núñez, 2♀, 1 immature (MACN-Ar 27113).

COMMENTS: The specimens with catalog number MACN-Ar 27113, unlike other males assigned to this species, lacks the silver color on the back of the abdomen and the palp tibia is thick. However, they have a similar morphology of the copulatory bulb, the booklungs with dark markings, and the prolongation of the chelicerae is cuspless. We have chosen the most conservative action, and include those specimens in this species, despite the minor differences.