Actinopus excavatus, 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 : 76-81

Actinopus excavatus , sp. nov.

Figures 39A–H, 40A–D, 46

TYPE MATERIAL: HOLOTYPE ♂ (MACN-Ar 36629): Córdoba: Calamuchita [32°16′ S 64°37′ W], Mar,-Apr, 1958, Viana, 1♂. PARATYPE: 1♀ (MACN-Ar 36630), Cerro Colorado [30°6′ S 63°55′ W], 20 Sep, 1959, March.

ETYMOLOGY: The specific name refers to the deep depression in the center of the sternum.

DIAGNOSIS: Actinopus excavatus can be distinguished from A. goloboffi by the absence of projections in the anterior angle of coxae I–II; males also differ by the presence of a thinner and more slender bulb (fig. 39E–G). Females differ from others of type III morphology by the spermathecae smaller and subquadrate (fig. 40C), with a small external apical lobe. The species differs from A. balcarce , by the poorly developed BTA, well-developed ATA, and the larger number of retrolateral thorns on tibia II.

DESCRIPTION: Holotype male (MACN-Ar 36629, figs. 39A–H): Total length: 11.40. Carapace (fig. 39A): length 4.32, width 4.20. Cephalic region: length 2.70, width 2.82; clypeus with a central bristle and 3–4 small ones to the sides, 14 bristles between PME and 4–5 behind each PME-PLE dyad; with 4–5 small bristles and a larger one on each side of the OQ, and 1-1 behind (along medial line). Fovea (fig. 39B): length 0.90, width 1.50. Eyes, diameters and inter- distances: AME 0.12, ALE 0.32, PME 0.16, PLE 0.20, OQ length 0.76, anterior width 2.16, 3.06 posterior width; AME-ALE 1.52, PME-PLE 0.08, AME-PME 0.40, ALE-PLE 0.40, AME-AME 0.28. Chelicerae: Length 1.92, width 1.08, with shallow dorsal ridges. Cheliceral apex with 10 recumbent and elongated bristles that cover the base of the fang. Rastellum with 9 marginal blunt cusps and 4 small dorsal attenuated ones. Cheliceral furrow with 6 large promarginal teeth and 4 retromarginal and 10 denticles, near the promarginal teeth. Labium: length 0.88, width 0.80. Maxillae: anterior length 1.14, posterior length 1.92, width 1.98. Sternum (fig. 39H): Length 3.00, maximum width 2.80, minimum width 0.84. Postlabial sigillum shallow, posterior sigilla shallow, converging toward central depression. Abdomen: Length 4.20, with dark bristles and lateral grooves. PMS: length 0.48; PLS: length of basal:medial:apical segments 0.48:0.20:0.08. Spigots: 1 large, 29 small on PMS; PLS, numbers of large(small) spigots on basal:medial:apical article 1(30):2(32):(50). Lengths of legs and palp: 4.50, 1.86, 2.70, 3.36, 2.10, 14.52. II: 4.32, 1.80, 2.58, 3.54, 2.10, 14.34. III: 3.30, 1.80, 2.10, 3.72, 2.40, 13.32. IV: 4.50, 1.98, 3.30, 3.90, 2.40, 16.08. Palp: 5.40, 2.70, 4.32, –, 1.08, 13.50.

Chaetotaxy: Femora: 0. Patellae: I-II, 0; III, 30 P SUP-D ANT +10 on the margin, 1 P A INF, 1 D B, 9 R A +10 on the margin; IV, 56 P SUP-D ANT, 1 P A. Tibiae: I, 1-1-1-1-1-1-3 R INF, 1-2- 1-1-1-2-1-2-1-4 V; II, 2-2-1-2-3-2-4-3-3 R INF, 2-1-2-1-1-4 V; III; 1-1-2-1 P, 1 D B, with a crown of 22 thorns, 3-3-5-2-2 R, 1-3 V (1:2 A); IV, 1 P M, 2-2-4 V. Metatarsi: I, 2-1-1-2-2-2-1-2 V, 1-3- 2-2-2-3-1-2-4 V POST-R INF, 2-2-3-1-3-1-1-2 V ANT; II, 1-1-1-1-1-1-1-1-1-1 P INF, 1-1-1-2-1- 1-1-4-2-3-3-2-3-1-3 R INF-V POST, 3-1-2-1-4- 4-1-3-3-1-3 V; III, 1-2-0-1-1-2 D POST, 1-1-1-1-1 D ANT, 2-3-1-1-2-1-2-3-3 V ANT-P INF, 1-2-2- 1-3-1-5 V POST-R INF; IV, 2-2-1-1-3-2 P (3:4 A), 1-1 R (1:2 A), 2-0-2-3 V. Tarsi: I, 1-1-1-1-1- 1-1 P INF, 1-2-2-2-1-1-4-3 R INF, 1-1-0-1-1 V; II, 1-2-2-2-2-1-2-2-1-1 P INF, 26 R INF, 1-1-1-1- 1-2 V; III, 1-0-2-1-2-5-1-1-4 P INF, 4-1-2-1-2-2- 1-3-6-4-1 R INF, 1 V A; IV, 1-2-1-3-1-3-4-1-4-3 P INF, 2-1-2-2-1-1-3 R INF. Total number of retrolateral spines on tibiae I and II (fig. 39D): 9 and 22 respectively. Palp: Tibia long and slender (width/length: 0.28±0.004) (fig. 39C). Bulb (fig. 39E–G), BTA poorly developed and ATA well developed; embolus with a series of denticles at the base and Ak extending to the apex. Pseudoscopula: tarsi: I-II, sparse (uniformly distributed throughout the segment); III-IV, dense and uniform. Trichobothria: Tibiae: I-II 3-4; III 4-5; IV 5-6. Metatarsi: I 10; II 12; III 11; IV 6. Tarsi: I 10; II-III 9; IV 7. Color: Carapace and chelicerae dark reddish brown. Abdomen dark brown, booklungs with dark markings. Spinnerets yellowish. Sternum, labium, and maxillae light reddish brown. Legs as the carapace, tarsi lighter.

Paratype female (MACN-Ar 36630, figs. 40A– D): Total length: 18.96. Carapace (fig. 40A): length 5.70, width 5.34, with 10 bristles on each posterior margin. Cephalic region: length 3.72, width 4.20; clypeus with 30 bristles, chilum with 15 small ones, 20 bristles between PME and 3–5 behind each PLE-PME dyad, 1-1 bristles in the line to the fovea, 6–8 bristles on each side of the OQ. Fovea: length 1.02, width 2.10. Eyes, diameters and interdistances: AME 0.12, ALE 0.28, PME 0.20, PLE 0.24, AME-ALE 0.80, PME-PLE 0.12, AME-PME 0.56, ALE-PLE 0.56, AME- AME 0.32, OQ length 0.96, anterior width 2.68, 2.60 posterior width. Chelicerae: Length 2.22, width 1.74, slight dorsal grooves 1:3 A. Cheliceral apex with 9 recumbent and elongated bristles covering the base of the fang; dorsal anterior region with surface grooves. Rastellum with 9 marginal, blunt cusps, and 11 small dorsal ones. Fang groove with 4 large promarginal teeth and 5 retromarginal ones (a small one between 3d-4th) and 6 denticles in the furrow, near the promargin. Labium: length 1.36, width 0.92, with 11 anterior cuspules. Maxillae: anterior length 1.44, posterior length 1.92, width 1.6, with +80 cuspules 1:3 V ANT, extending to the anterior face. Sternum (fig. 40D): Length 3.68, maximum width 3.56, minimum width 0.84. Postlabial sigillum shallow; posterior sigilla converging toward central depression. Abdomen: Length 7.80, with small bristles, long in the dorsum. PMS: length 0.60; PLS: length of basal:medial:apical segments 0.88:0.44:0.28. Spigots: 3 large, 35 small on PMS; PLS, numbers of large(small) spigots on basal:medial:apical article 6/8(63):10(60):6(65). Lengths of legs and palp: I: 2.70, 1.80, 1.26, 1.50, 0.78, 8.04. II: 2.82, 1.86, 1.26, 1.80, 0.78, 8.52. III: 2.82, 2.10, 0.90, 1.92, 0.78, 8.52. IV: 3.30, 2.16, 1.92, 2.10, 0.78, 10.26. Palp: 2.70, 1.80, 1.80, –, 1.86, 8.16.

Chaetotaxy: Femora: 0. Patellae: I-II, 0; III, 16 P (1:2 A) +11 on the margin, 26 R (1:2 A) +17 on the margin; IV, 61 P SUP-D ANT; palp, 1-1- 1 P. Tibiae : I, 1 P A, 9 R INF, 1-1 V POST (1:3 A) ; II, 77 R (3:4 A), 1-1 V POST; III, 1 D B, with crown of 18 thorns and 6 apicals (on the apex, anterior to the crown) 58 R; IV, 1-1- 1-1 P (1:2 A, thin); palp, 8 P (serial), 15 R INF (3:4 A). Metatarsi : I, 17 P INF, 12 R INF, 1-1- 1-2 V POST ; II, 1-1-2-1-1-2 P INF, 14 R INF, 1-1-2 V POST; III, 15 D ANT, 16 D B (7-9 divided by a glabrous line), 37 on row D POST-R (more abundant R A), 1 V A POST; IV, 8 P (3:4 A), 1 D A ANT, 1 V A ANT. Tarsi : I, 7 P INF, 11 R INF, 2 V A ; II, 6 P INF (serial), 13 R INF, 2 V A; III, 38 R, 31 V-P; IV, 37 V-P; palp, 14 P INF, 20 R INF, 1 V A. Total number of retrolateral spines on tibiae I and II (fig. 40B): 9 and 77 respectively. Trichobothria: Tibiae: I 3-4 ; II 4-6 ; III 4-5 ; IV 5-5 . Metatarsi : I 11 ; II 12 ; III 11 ; IV 5 . Tarsi: I 11 ; II 12 ; III 10 ;

IV 6. Color: Carapace light reddish brown, chelicerae dark. Abdomen lighter brown, booklungs with dark markings. Sternum reddish brown, labium, and maxillae darker. Spinnerets yellowish. Legs as the carapace.

DISTRIBUTION: Province of Córdoba.

OTHER MATERIAL EXAMINED: Córdoba: El Sauce, Calamuchita [31°58′ S 64°33′ W], Dec, 1938, Exc. I.M. Viana, 1♂ (MACN-Ar 36631).