Occidenchthonius riopar, Zaragoza, Juan A., 2017

Zaragoza, Juan A., 2017, Revision of the Ephippiochthonius complex in the Iberian Peninsula, Balearic Islands and Macaronesia, with proposed changes to the status of the Chthonius subgenera (Pseudoscorpiones, Chthoniidae), Zootaxa 4246 (1), pp. 1-221 : 193-195

Occidenchthonius riopar n. sp. ( Figs 304–308 )

Type locality. Spain, Castilla-La Mancha, Albacete province, Riopar , Cueva del Farallón (38°27′10″N, 02°26′14″W; 1070 m a.s.l.).

Distribution. Spain: Castilla-La Mancha.

Etymology. Noun in apposition from the municipal area of Riopar , in which the type locality is situated.

Diagnosis (♀). A medium-sized, hypogean Occidenchthonius species of the verai -group. Movable cheliceral finger without isolated subapical tooth (di) and with prominent spinneret in female, unknown for male, lyrifissure ldb absent; without eyes or eye-spots, anterior margin of carapace prominent and without preocular microsetae, posterior margin with 2 macrosetae; chelal hand depressed at level of ib / isb, with a short, low hump distad of ib / isb and gentle slope between trichobothria ib / isb and eb; trichobothrium ist level with lyrifissure fb; fixed chelal finger with 19 teeth; distal half of movable chelal finger with 12 pointed teeth with dental canals, basal half of movable chelal finger with 6 rounded, partially fused, vestigial teeth, without canals, on raised lamina; pedipalpal femur (♀) 6.5 times longer than broad, length 0.78 mm; chela (♀) 5.6 times longer than deep, length 1.09 mm; ratio movable chelal finger/chelal hand (♀) 1.5; lacking lyrifissures ma1, ma2 and hp, all other chelal lyrifissure patterns present with their standard complements.

Type material examined. ♀ holotype ( DEUA), Spain, Castilla-La Mancha, Albacete province, Riopar , Cueva del Farallón (38°27′10″N, 02°26′14″W; 1070 m a.s.l.), 21.XI.1992, leg. J.L. Lencina.

Description (♀; ♂ unknown). Medium-sized, hypogean, moderately troglomorphic species. Integument depigmented; weak hispid granulation on lateral surfaces of carapace, on cheliceral hand and on bases of chelal fingers.

Carapace ( Fig. 305 ) as long as broad and constricted posteriorly; medial part of anterior margin prominent, without a well-defined epistome, and strongly dentate ( Fig. 304 ). Without eyes or eye-spots. Chaetotaxy: 18 setae, without preocular microsetae, 2 setae in posterior row, formula 4:6:4:2:2, anteromedial setae 0.13 mm long, sublateral ocular setae 0.07 mm; 4 lyrifissures anteriorly and 2 posteriorly.

Chelicera ( Figs 306, 307 ) with 6 setae and 1 lateral microseta on hand, seta vb very short (0.030 mm long), microsetae 0.025 mm; hand with 4 dorsal and 1 ventral lyrifissure, lyrifissure ldb absent. Fixed finger with 10 teeth decreasing in size proximally, two distal teeth distinctly larger than others, 7 proximal microtubercles. Movable finger without an isolated subapical tooth (di), with 7 teeth decreasing in size proximally and 3 proximal microtubercles, the distal tooth larger than others; spinneret prominent in female ( Fig. 307 ), unknown for male; seta gl 0.51 from base of movable finger.

Chaetotaxy of tergites 4:4:4:4:6:6:6:6:1T2T1:4:1T2T1:0, tergites IX and XI each with 2 sublateral tactile setae (0.25 and 0.27 mm long, respectively). Chaetotaxy of sternites 10:(3)7(3):(2)7(2):7:6:6:6:6:2T1T2:0:2, lateral setae on sternite III macrosetal in size, sternite X with 2 submedial tactile setae.

Pedipalpal coxa with 5 setae (including 2 on manducatory process), distal marginal seta of disk 0.12 mm long; coxa I 3 + 3 marginal microsetae, distal marginal seta 0.06 mm long; II 4 + 10 bipinnate coxal spines, III 5 + 4 bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.

Pedipalp with femoral chaetotaxy 3:6:3:6:1. Chela ( Fig. 308 ) with hand depressed at level of ib / isb, with a short, low hump distad of ib / isb and gentle slope between trichobothria ib / isb and eb; weak hollow before base of movable finger with thicker cuticle; width shorter than depth; chaetotaxy 4:5:4–5, seta ph3 present and duplicated on one chela, seta dh3 removed close to the intermediate setal row; distal end of hand and bases of chelal fingers with sclerotized condylar complex. Fixed finger with 19 pointed teeth and with dental canals, first two distal teeth small, third tooth of normal row (mt) of fixed finger distinctly modified in shape and deviated in orientation with respect to the others, dental row reaching up to proximad of trichobothrium sb; tip of fixed finger with an accessory tooth (td) on antiaxial face; one pair of long and close together antiaxial sensory setae (as) at the base, both distad of lyrifissure fb, 0.055 mm long, distance between them 0.030 mm, fixed finger depth at the base 0.070 mm; 4 teeth at level of est / it occupying 0.1 mm, distance between successive apices 0.025–0.030 mm. Distal half of movable finger with 12 mostly pointed teeth and with dental canals that reach up to slightly proximad of halfway between trichobothria st and sb, the distal one very tiny and on low tubercle, the most proximad rounded; basal half of movable chelal finger with 6 rounded, partially fused, vestigial teeth, without canals, on raised lamina; dental row reaching up to proximad of trichobothrium sb; basal apodeme long and apically narrowed; coupled sensilla pc slightly closer to sb than to b. Trichobothria as in Fig. 308 ; trichobothrium ist strongly distad of esb and level with lyrifissure fb; distance between ib / isb and esb slightly longer than that between ib / isb and the base of the hand; distance between st and sb 2.1 times longer than that between sb and b; lacking lyrifissures ma1, ma2 and hp, all other chelal lyrifissure patterns present with their standard complements.

Measurements and ratios. Female holotype: Body 1.25. Carapace 0.45/0.45 (1.0). Chelicera 0.46/0.26 (1.8), movable finger 0.24. Pedipalp: femur 0.78/0.12 (6.5), patella 0.32/0.15 (2.1), chela 1.09/0.20 (5.6), hand 0.43 (2.2), movable finger 0.65; ratio movable finger/hand 1.5, femur/movable finger 1.2, femur/carapace 1.7, chela/carapace 2.4, chela/femur 1.4.

Remarks. Within the verai -group, O. riopar n. sp. shares with O. cazorlensis , O. hoerwegi n. sp. and O. mateui n. sp. a short row of only 3–8 low and rounded vestigial teeth in the basal third of the movable chelal finger, but it differs from them by the position of trichobothrium ist, level with lyrifissure fb in O. riopar n. sp. versus distinctly proximad in the others.

Figures

FIGURES 304 – 308. Occidenchthonius riopar n. sp., female holotype. 304, anterior margin of carapace, partial view; 305, carapace; 306, left chelicera; 307, fingers of left chelicera, partial view; 308, left chela, antiaxial view.