Cantabrochthonius, 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 : 23-24

Genus Cantabrochthonius n. gen.

Diagnosis. Genus of the tribe Chthoniini with ephippiochthonian chela, weakly depressed at level of trichobothria ib / isb, distad of these trichobothria with a long hump, followed by an abrupt slope towards base of fixed finger, giving the dorsum a step-like appearance in lateral view; without hollow before base of movable finger; base of chelal hand moderately constricted on paraxial side; medial protuberance (ip) between chelal condyles is prominent, bow-like, slightly closer to the paraxial condyle; distal end of hand and bases of chelal fingers with strongly sclerotized condylar complex; proximal portion of chelal hand with only 3 setae in adults and tritonymphs, seta ph3 lacking, chaetotaxy: 4:5:3 ( Figs 24, 25 ); setae ih3 and frequently ih4 well distad of ih1 and ib / isb. Both chelal fingers almost straight, axis of fixed finger apically forming a slightly obtuse angle; dental rows homodentate, teeth spaced, upright, without saw-like dentition, third tooth of normal row (mt) of fixed finger not modified; tip of fixed finger with an accessory tooth (td) on antiaxial face; tip of fixed chelal finger of male and tritonymph with a deep hollow on paraxial face and a subapical protuberance (sp), lacking in female; coupled sensilla pc usually distinctly distad of trichobothrium sb; base of movable chelal finger with an enlarged sclerotized condyle (bc) and a well developed apodeme. Lyrifissures ma1 and ma2 present, hd absent. Anterior margin of carapace almost straight, without epistome, more strongly dentate between median macrosetae. Coxae II and III with coxal spines; intercoxal tubercle absent ( Fig. 28 ); distal marginal seta of pedipalpal coxa disk (dps) markedly shorter than that of coxa I (dcs) ( Fig. 28 ); sternite III in male and female usually with 10 marginal setae, of which the lateral one on each side is a microseta. Male genitalia without a median hiatus dividing each row of guard-setae. Comparison with related genera as in the key and Table 1 .

Type species. Chthonius (Ephippiochthonius) asturiensis Beier, 1955 .

Etymology. Derived from Cantabria, with reference to the known distribution range of the genus in the Cantabrian area, and the suffix Chthonius .

Distribution. SPAIN: Asturias, Cantabria, Castilla y León, Basque Country and Navarra communities.

Remarks. As noted above, the presence/absence of an intercoxal tubercle between coxae III and IV has been considered by most specialists to be an important characteristic for separating genera within the superfamily Chthonioidea. Cantabrochthonius n. gen. shares with Ephippiochthonius some distinctive characteristics, such as the absence of seta ph3 and the presence of an intercondylar protuberance (ip) on the chelal hand. The main difference between these two genera is the absence of an intercoxal tubercle in Cantabrochthonius , but they can also be separated by the length ratio of setae dps / dcs, which is markedly lower in Cantabrochthonius , and position of chelal hand seta ih3, well distad of ih1. Additional differences are the absence of the chelal hand lyrifissure hd and the shape of the lamina in the basal half of the movable chelal finger in Cantabrochthonius n. gen., which in these respects resembles the Ephippiochthonius species of the fuscimanus -group, but it differs from the latter in the presence of lyrifissure ma2.

Cantabrochthonius n. gen. most probably evolved from an Ephippiochthonius ancestor, but developed some important differences. Currently C. asturiensis is a successful species, which has become widespread in five communities in the North of Spain.

Figures

FIGURES 24 – 25. Cantabrochthonius asturiensis (Beier, 1955) n. comb., male (24) and female (25) from Burgos province, Spain. 24, right chela; 25, left chela.

FIGURES 26 – 31. Cantabrochthonius asturiensis (Beier, 1955) n. comb., female holotype (26, 31) and male, Burgos province, Spain (27 – 30). 26, carapace, partial view; 27, carapace, partial view; 28, coxae; 29, right chelicera; 30, fingers of right chelicera, partial view; 31, movable finger of right chelicera, partial view. See Material and methods for abbreviations.