Sidydrassus tianschanicus
Creators: name: Fomichev, Alexander A.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Gnaphosidae
Sidydrassus
Sidydrassus tianschanicus

description: Sidydrassus tianschanicus (Hu & Wu, 1989)
Figs 2, 8, 16–18, 22–24, 42–44
Drassodes tianschanica Hu & Wu, 1989: 260, figs 212.1–4 (♂ ♀).
Sidydrassus tianschanica: Esyunin & Tuneva 2002: 177, figs 58–59 (♂ ♀, transferred from Drassodes).
Sidydrassus tianshanicus: Song et al. 2004: 224, figs 132A–D (♂ ♀).
Sidydrassus tianschanica: Tuneva 2004: 326, figs 43 (♂).
Material examined. KAZAKHSTAN: Almaty Oblast: 3♂ (ISEA, 001.8937), Ili River valley (right side), c. 40 km NNW from Kaptshagai Town, 44°15’N, 76°54’E, loess cliff on river bank, 430 m, 16.04.2016, A.A. Fomichev; 1♂ (ISEA, 001.8938), 1♂ (ISEA, 001.8939) same locality and date, without precise data on habitat, R.Y. Dudko.
Diagnosis. In having a large median apophysis (Ma) without a prolateral bent branch, the male of S. tianschanicus is similar to that of S. saiynovi sp. n., from which it can be distinguished by the RTA twice shorter than tibia (vs. equal length in S. saiynovi sp. n.), the straight embolus (Em) (vs. bent prolaterad in S. saiynovi sp. n.) and the median apophysis (Ma) of almost the same length as the embolus (vs. twice shorter in S. saiynovi sp. n.) (cf. Figs 16–18, 23 and 13–15, 20). In having a wide and round epigynal fovea (Fo) and the simple posterior receptacles (Pr) without pronounced heads, the female of S. tianschanicus is very similar to that of S. rogue but differs in the epigynal proportions: the epigynal fovea of S. tianschanicus is 2.1 times longer than wide (vs. 1.7 times longer in S. saiynovi sp. n.) and the anterior (Ar) and posterior receptacles (Pr) are equal in size (vs. the anterior receptacles significantly larger than the posterior ones in S. rogue sp. n.) (cf. Figs 42–43 and 40–41).
Description. Male. Total length 10.5. Carapace: 4.6 long, 3.1 wide. Colouration. Carapace light brown, darker anteriorly. Chelicerae dark brown. Endites and labium brown. Sternum and coxae yellow-brown. Palps and legs yellow-brown, darker distally. Abdomen cream-coloured. Spinnerets light yellow. Leg measurements: I: 4.05, 2.2, 3.85, 3.25, 2.0 (15.35). II: 3.6, 2.0, 3.0, 2.7, 1.9 (13.2). III: 3.3, 1.65, 2.45, 2.6, 1.7 (11.7). IV: 4.25, 1.9, 3.3, 4.15, 1.9 (15.5). Leg spination: I: Fe d1-1-0 p0-1-1; Ti p1-0-0 v1-2-0; Mt v2-0-0. II: Fe d1-1-0 p0-1-2; Ti p1-0-1 v0-2-0; Mt v2-0-0. III: Fe d1-1-1 p0-1-1 r0-2-1; Ti d1-0-0 p1-1-1 r0-1-1 v1-2-2; Mt d0-1-0 p1-1-0 r1-0-0 v2-1-0. IV: Fe d1-1-1 p0-1-1 r0-1-1; Ti d1-0-1 p1-1-1 r1-1-1 v2-2-2; Mt d1-2-0 p1-1-0 r1-1-0 v2-2-0.
Palp as in Figs 16–18, 22–24. Tegulum (Te) 1.6 times longer than wide. Sperm duct (Sd) poorly visible in ventral view. Median apophysis (Ma) strongly bent prolaterad. Membrane of median apophysis (Mm) reduced. Triangular membrane (Tm) between embolus and median apophysis well-developed, elongated. Conductor (Cn) originates at a 12 o’clock position. Embolus (Em) slightly longer than median apophysis, with a thick base (Eb) and almost straight apex.
Epigyne as in Figs 42–43. Fovea (Fo) cross-inclined, with very thin lateral margins. Median plate (Mp) inverted triangle-shaped.Anterior receptacles (Ar) diverging, separated by 0.75 times of their diameter. Posterior receptacles (Pr) ovoid, without pronounced heads.
Distribution. The species was described from Xinjiang Province of China (Hu & Wu 1989). It was earlier reported from Kazakhstan by Logunov et al. (2012), who provided no details on the material studied or the locality. A new record from Almaty Oblast of Kazakhstan confirms that this species indeed occurs in this country (Fig. 44). This species appears to have one of the widest ranges in the genus. Only the generotype has a larger range.
Comments. Tuneva (2004) pointed out the RTA is markedly shorter in S. tianschanicus in comparison to that of congeners, suspecting that it was just broken in the type specimen. Indeed, the newly collected males from Kazakhstan have a long RTA, similar to all other known members of the genus.
description: Published as part of Fomichev, Alexander A., 2022, A survey of the East Palaearctic Gnaphosidae (Araneae). 12. A review of Sidydrassus Esyunin & Tuneva, 2002, pp. 260-272 in Zootaxa 5194 (2) on pages 264-265, DOI: 10.11646/zootaxa.5194.2.7, http://zenodo.org/record/7147403