Sidydrassus, Esyunin & Tuneva, 2002

Fomichev, Alexander A., 2022, A survey of the East Palaearctic Gnaphosidae (Araneae). 12. A review of Sidydrassus Esyunin & Tuneva, 2002, Zootaxa 5194 (2), pp. 260-272 : 270-271

Key to Sidydrassus species

Males

1 Median apophysis with a prolaterally bent branch ( Figs 25, 29 )........................................ S. shumakovi - Median apophysis without a prolaterally bent branch ( Figs 13, 16 , 20, 23 , 31, 35 ).................................. 2 2 RTA 4 times shorter than tibia ( Figs 31–33 )............................................................ S. rogue - RTA as long as tibia or twice shorter than tibia ( Figs 13–18 )................................................... 3 3 RTA as long as tibia ( Figs 13–15 )............................................................ S. saiynovi sp. n. - RTA twice as short as tibia ( Figs 16–18 )....................................................... S. tianschanicus

Females (female of S. saiynovi sp. n. is unknown)

1 Epigynal fovea slit-shaped, not contiguous with the epigastric furrow ( Figs 37–38 )........................ S. shumakovi

- Epigynal fovea wide and round, contiguous with the epigastric furrow ( Figs 40, 42 )................................ 2

2 Epigynal fovea 2.1 times longer than wide, anterior and posterior receptacles equal in size ( Figs 42–43 )........................................................................................................ S. tianschanicus

- Epigynal fovea 1.7 times longer than wide, anterior receptacles significantly larger than the posterior ones ( Figs 40–41 )................................................................................................... S. rogue

Possible relationships within Sidydrassus

Of the four species currently assigned to the genus, S. saiynovi sp. n., S. tianschanicus , and S. rogue seem to be closely related as they are similar in having the median apophysis without a prolateral branch, similar proportions of the embolic base, the wide epigynal fovea, the diverging anterior receptacles and posterior receptacles without pronounced heads ( Figs 13, 16 , 20, 23 , 31, 35 , 40–43 ). The generotype, S. shumakovi , stays apart and possesses the median apophysis with a prolateral branch, the thick embolic base, the slit-shaped epigynal fovea, the converging anterior receptacles and the posterior receptacles with pronounced heads ( Figs 25, 29 , 37–39 ). Thus, all the Sidydrassus species can be divided into two species groups: the shumakovi -group (one species) and the tianschanicus -group (three species) ( Table 1 ).

Figures

FIGURES 25–30. Male palp (25–27) and bulb (28–30) of Sidydrassus shumakovi. 25, 29—ventral; 26—dorsal; 27, 30—retrolateral; 28—prolateral. Scale bars: 0.2 mm. Abbreviations: Cn conductor, Eb embolic base, Em embolus, Lb prolateral branch of the median apophysis, Ma median apophysis, Mm membrane of the median apophysis, Sd sperm duct, Te tegulum, Tm triangular membrane.

FIGURES 13–18. Male palps of Sidydrassus saiynovi sp. n. (13–15) and S. tianschanicus (16–18). 13, 16—ventral; 14, 17—dorsal; 15, 18—retrolateral. Scale bars: 0.2 mm.

FIGURES 19–24. Bulbs of Sidydrassus saiynovi sp. n. (19–21) and S. tianschanicus (22–24). 19, 22—prolateral; 20, 23—ventral; 21, 24—retrolateral. Scale bars: 0.2 mm. Abbreviations: Cn conductor, Eb embolic base, Em embolus, Ma median apophysis, Mm membrane of the median apophysis, Sd sperm duct, Te tegulum, Tm triangular membrane.

FIGURES 31–36. Male palp (31–33) and bulb (34–36) of Sidydrassus rogue. Scale bars: 0.2 mm. Abbreviations: Cn conductor, Eb embolic base, Em embolus, Ma median apophysis, Mm membrane of the median apophysis, Sd sperm duct, Te tegulum, Tm triangular membrane.

FIGURES 37–43. Epigynes of Sidydrassus shumakovi (37–39), S. rogue (40–41) and S. tianschanicus (42–43). 37—intact, ventral; 38, 40—macerated, ventral; 39, 41—macerated, dorsal; 42—ventral; 43—dorsal; 42–43—after Song et al. (2004). Scale bars: 0.2 mm. Abbreviations: Ar anterior receptacle, Cp copulatory opening, Fo fovea, Lm lateral margin of the fovea, Mp median plate, Pr posterior receptacle, Rh head of the posterior receptacle.