Chthonius (Chthonius) heterodactylus C.L. Koch 1843
Creators: name: Gardini, Giulio
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Chthoniidae
Chthonius
Chthonius heterodactylus
Chthonius heterodactylus group

description: Key to adults of species of the Chthonius heterodactylus group from the eastern Alps and the Carpathians
1. Epigean or endogean eyed species, rarely with slightly troglomorphic facies; carapace with 18 macrosetae: anterior row with or without preocular microsetae, ocular row with 6 macrosetae (Figs 4–5, 14, 83); tergites I–II with 4 setae each; movable chelal finger with 16–38 reclined (Figs 23–26, 80–81) or partially erect teeth (Figs 9–11); chela 4.8–6.9 (♂) or 4.3–5.9 (♀) times as long as deep, ratio of pedipalpal femur/carapace 1.15–1.98 (♂♀)........................................ 2
- Hypogean anophthalmic species with strongly troglomorphic facies; carapace with 16 macrosetae: chaetotaxy 4:m 4m:4:2:2(18), rarely m 4m:4:4:2:2(18), lateral microsetae with variable position from ocular to anterior row; ocular row with 4 macrosetae (Fig. 44); tergites I–II with 2 setae each; movable chelal finger with 35–54 contiguous, reclined triangular teeth (Figs 48–49); pedipalps usually more slender: chela 6.6–7.6 (♂) or 6.1–7.3 (♀) times as long as deep, ratio of pedipalpal femur/carapace 1.75–2.15 (♂♀)................................................. C. lessiniensis Schawaller, 1982
2. Fixed chelal finger with distal paraxial seta gradually acuminate and curved, not thickened or only weakly so (Figs 18–19, 24–26, 56–58); carapace with (Figs 12–13, 20) or without (Figs 50–52) epistome and with 1 or 2 lateral microsetae on each side of anterior row and usually 1 lateral microseta on each side of posterior row; fixed chelal finger usually without intercalary microdenticles (Figs 23–26, 56–58).................................................................. 3
- Fixed chelal finger with distal paraxial seta spatulate, thickened in the middle (Figs 9–10, 80–81); carapace without epistome (Figs 1–3, 75–76) and usually without lateral microsetae on anterior and posterior rows; fixed chelal finger usually with intercalary microdenticles (Figs 9–10, 86–87)................................................................. 5
3. Carapace with epistome (Figs 12–13, 20) and with two lateral microsetae on each side in anterior row (Figs 14, 21); fixed and movable chelal fingers respectively with 18–50 and 18–38 teeth; fixed chelal finger with distal paraxial seta gradually sharp and curved, not enlarged (Figs 18–19, 24–26); coupled sensilla pc of movable chelal finger usually between trichobothria st and sb; species from Carpathians........................................................................ 4
- Carapace without epistome (Figs 50–52) and with 1 lateral microseta on each side on anterior row (Fig. 53); fixed and movable chelal fingers respectively with 16–22 and 18 teeth; fixed chelal finger with distal paraxial seta sinuous and weakly enlarged (Figs 56–58); coupled sensilla pc of movable chelal finger between trichobothria sb and b; species from Eastern Alps of Austria and Slovenia .................................................................... C. pusillus Beier, 1947
4 Fixed chelal finger with sharp, reclined and spaced teeth increasing in size as far as halfway along the finger, then reduced in size towards the base (Figs 23–31); fixed and movable chelal fingers respectively with 18–32 and 18–30 teeth; ratio of movable finger/hand of chela usually 1.8–1.9 (♂) or 1.6–1.7 (♀); genital opening of male flanked by 9–14 scattered setae on each side (Fig. 17)............................................................ C. heterodactylus Tömösváry, 1882
- Fixed chelal finger with distal teeth contiguous, pointed or apically rounded, slightly inclined backwards, followed proximally by large, sharp, reclined and spaced teeth and 9–21 proximal teeth low, contiguous, rounded, reduced in size towards the finger base (Figs 39–41); fixed and movable chelal fingers respectively with 34–50 and 28–38 teeth; ratio of movable finger/hand of chela 2.0–2.2 (♂) or 1.9–2.0 (♀); genital opening of male flanked by 6–8 aligned setae on each side................................................................................................. C. hungaricus Mahnert, 1981
5. Distal half of movable chelal finger (♂♀) with 8–15 triangular, sharp, higher than wide teeth, erect or weakly forward-inclined (Figs 9–11)................................................................. C. cavernarum Ellingsen, 1909
- Distal half of movable chelal finger (♂♀) usually with 11–15 low, broad, reclined teeth (Figs 65–66, 80–81), rarely with 6–10 triangular reclined teeth, wider than high (Figs 88–89).................................. C. raridentatus Hadži, 1930
description: Published as part of Gardini, Giulio, 2014, The species of the Chthonius heterodactylus group (Arachnida, Pseudoscorpiones, Chthoniidae) from the eastern Alps and the Carpathians, pp. 101-137 in Zootaxa 3887 (2) on page 103, DOI: 10.11646/zootaxa.3887.2.1, http://zenodo.org/record/228058