Ephippiochthonius distinguendus ( Beier, 1930 ) Beier, 1930

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 : 69-70

Ephippiochthonius distinguendus ( Beier, 1930) , n. comb.

( Figs 96–99 )

Chthonius (Ephippiochthonius) distinguendus Beier 1930: 326 , fig. 4. Chthonius (Ephippiochthonius) distinguendus: Zaragoza 2007: 16 .

Type locality. Spain, Basque Country, Guipúzcoa province , Albistur, Cueva de Mendicute (43°08′33″N, 02°07′33″W; 658 m a.s.l.).

Distribution. Spain: Basque Country.

Diagnosis (♀). A moderately large, hypogean Ephippiochthonius species of the tetrachelatus -group. Movable cheliceral finger without isolated subapical tooth (di) and with prominent spinneret, lyrifissure ldb present; no eyes or eye-spots, 2 preocular microsetae on each side, posterior margin of carapace with 2 macrosetae; chelal hand distinctly depressed at level of ib / isb, with low and rounded hump distad of ib / isb and gentle slope between trichobothria ib / isb and eb; some denticles intercalated between some teeth of both chelal fingers; fixed chelal finger with 20 teeth; movable chelal finger with 16 teeth with dental canals, without marginal lamina; pedipalpal femur (♀) 7.8, times longer than broad, length 0.94 mm; chela (♀) 6.8 times longer than deep, length 1.29 mm; ratio movable chelal finger/chelal hand (♀) 1.9; all chelal lyrifissure patterns present, most with their standard complements, hd presence is doubtful.

Type material examined. ♀ holotype ( MNCN), Spain, Basque Country, Guipúzcoa province, Albistur, Cueva de Mendicute (43°08′33″N, 02°07′33″W; 658 m a.s.l.), without collecting date, leg. C. Bolivar.

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

Carapace ( Fig. 97 ) distinctly longer than broad and posteriorly constricted; medial part of anterior margin straight, without epistome, and strongly dentate ( Fig. 96 ); without eyes or eye-spots. Chaetotaxy: 18 macrosetae and 2 preocular microsetae on each side, formula mm 4mm:6:4:2:2, anteromedial setae 0.13 mm long, sublateral ocular setae short 0.05 mm, anteromedial setae well apart (distance 0.22 mm) and close to the anterolateral setae (distance 0.06 mm), preocular microseta 0.015 mm long, lyrifissures difficult to observe in the holotype.

Chelicera ( Fig. 98 ) with 6 setae and 1–2 lateral microsetae on hand, seta vb short (0.045 mm long), microseta 0.020 mm long; hand with 5 dorsal and 1 ventral lyrifissure, lyrifissure ldb present. Fixed finger with 11 teeth decreasing in size proximally, 2 submedial teeth distinctly larger than others. Movable finger without an isolated subapical tooth (di), with 8 teeth decreasing in size proximally, two subdistal teeth of equal size and larger than others; spinneret very prominent, pointed, tooth shape ( Fig. 98 ); seta gl 0.52 from base of movable finger.

Chaetotaxy of tergites 2:2:4:4:6:6:6:6:1T2T1:4:1T2T1:0; tergites IX and XI each with 2 sublateral tactile setae, tactile seta tergite XI 0.28 mm long. Chaetotaxy of sternites 11:(3)8(3):(2)7(2):8:6:6:6:6:2T1T2:0:2, lateral microsetae on sternite III apparently absent, sternite X with 2 submedial tactile setae.

Pedipalpal coxa with 5 setae (including 2 on manducatory process), distal marginal seta of disk 0.09 mm long; coxa I 4 + 3 marginal microsetae, distal marginal setae lost; II 5 + 13–14 bipinnate coxal spines, III 6 + 6 bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.

Pedipalp with femoral chaetotaxy 3:6:2:6:1. Chela ( Fig. 99 ) with hand distinctly depressed at level of ib / isb, with low and rounded hump distad of ib / isb and gentle slope between trichobothria ib / isb and eb; dorsal-antiaxial surface of the chelal hand between the hump and trichobothria eb / esb flattened, limited by a marked edge; ventral intercondylar bow-like protuberance (ip) present; width shorter than depth; chaetotaxy 4:5:3, seta ph3 lacking, setae ih1, ih3 and ih4 approximately level with trichobothria ib / isb; distal end of hand and bases of chelal fingers with sclerotized condylar complex. Fixed finger with 20 teeth, mostly pointed, the distal one small, of these the the 9 proximal teeth progressively decreasing in size from pointed to rounded, all with dental canals, subdistal and medial teeth distinctly elongated, dental row reaching up to distad of trichobothrium b, 2 microtubercles at base; both chelal fingers with intercalated denticles without dental canals between the normal teeth, 2–6 denticles between each pair of teeth from 4th to 14th distal teeth in the fixed finger and 2–5 denticles between each pair of teeth from 1st to 6th distal teeth in the movable finger; tip of finger with an accessory tooth (td) on antiaxial face; one single long (0.05 mm) antiaxial sensory setae (as) at the finger base of the single preserved chela, finger depth at the base 0.06 mm; only 2 teeth at level of est / it occupying 0.1 mm, distance between successive apices 0.053– 0.060 mm. Movable finger with 16 mostly pointed teeth with dental canals, progressively decreasing in size, dental row reaching up to level of sensilla pc; basal apodeme long and apically indented; coupled sensilla pc proximad of sb. Trichobothria as in Fig. 99 ; trichobothrium ist slightly distad of esb and well proximad of lyrifissure fb, trichobothria eb -esb -ist in a straight line; distance between ib / isb and esb equal to that between ib / isb and the base of the hand; distance between st and sb 1.6 times longer than that between sb and b. All chelal lyrifissure patterns present, most with their standard complements, hd presence is doubtful.

Measurements and ratios. Female holotype. Body 1.60. Carapace 0.51/0.48 (1.1). Chelicera 0.49/0.20 (2.5), movable finger 0.25. Pedipalp: femur 0.94/0.12 (7.8), patella 0.34/0.15 (2.3), chela 1.29/0.19 (6.8), hand 0.45 (2.3), movable finger 0.85; ratio movable finger/hand 1.9, femur/movable finger 1.1, femur/carapace 1.8, chela/carapace 2.5, chela/femur 1.4.

Remarks. Within the tetrachelatus -group, E. distinguendus shares with E. castellonensis n. sp. the presence of intercalated denticles on at least the fixed chelal finger. Comparisons between these species are made in the key and in the description of E. castellonensis n. sp. The above description incorporates in part that of Beier (1930).

Figures

FIGURES 96 – 99. Ephippiochthonius distinguendus (Beier, 1930) n. comb., female holotype. 96, anterior margin of carapace, partial view; 97, carapace, partial view; 98, fingers of left chelicera, partial view; 99, left chela, partial view.