Shaanxinus liangdang Irfan, Rehman, Wang & Zhang, 2026, sp. nov.

Shaanxinus liangdang sp. nov. Figs 5 A – D, 6 A – E, 10 H – J, 11 Chinese name. 两当陕蛛. Type material. Holotype: • 1 ♂, China, Gansu Province: Liangdang County, Zhangjia Township, Heihe Forest Park, 34°11.020'N, 106°32.300'E, alt. 1774 m, 2011-06-1, Wang Luyu leg. (SWUC -T-LIN-42-01). Paratypes • (28 ♂ 27 ♀): 2 ♂ 2 ♀, same data as holotype male (SWUC -T-LIN-42-02 – 05); • 1 ♂, Liangdang County, Yangdian Township, Yangdian Village, 33°56.320'N, 106°24.480'E, alt. 1004 m, 2011-05-31, Wang Luyu leg. (SWUC -T-LIN-42-06); • 3 ♂ 1 ♀, Shaanxi Province: Taibai Mountain, Benyue Old County Town, 33°47.544'N, 107°45.594'E, alt. 1761 m, 2009.05.25, Wang Luyu leg. (SWUC -T-LIN-42-07 – 10); • 4 ♂ 5 ♀, southern slope of Taibai Mountain (Zhou Zhihou’s site), 33°52.477'N, 107°48.814'E, alt. 1577 m, 2009.05.24, Wang Luyu leg. (SWUC -T-LIN-42-11 – 19); • 1 ♂, 33°52.954'N, 107°48.722'E, alt. 1577 m, 2009.05.24, Wang Luyu leg. (SWUC -T-LIN-42-20); • 9 ♂ 12 ♀, southern slope of Taibai Mountain (Zhou Zhihou’s site), 33°53.820'N, 107°47.946'E, alt. 1979 m, 2009.05.24, Wang Luyu leg. (SWUC -T-LIN-42-21 – 41); • 8 ♂ 7 ♀, Zhouzhi County, Juhouzhenzi, Back slope of Qingfenglou Farmhouse, 33°53.665'N, 107°48.198'E, alt. 1935 m, Li Zonggui, Xu Kaiyi, Wang Luyu leg. (SWUC -T-LIN-42-42 – 56). Etymology. The specific epithet is derived from the type locality. Diagnosis. The male of Shaanxinus liangdang sp. nov. resembles S. micangshan sp. nov. in having a similar embolic division (Figs 5 A, 7 A), but it can be distinguished by the anterior radical apophysis tip lacking a projection (Fig. 5 B), vs with a triangular projection in S. micangshan sp. nov. (Fig. 7 B); the distal arm of paracymbium covering more than half of the proximal part, with the tip tapering in retrolateral view (Fig. 5 B), vs the distal arm covering half of the proximal part and the tip margin straight in S. micangshan sp. nov. (Fig. 7 B). The epigyne of S. liangdang sp. nov. resembles S. shoukaensis Lin, 2019 in having a reduced ventral plate (Fig. 6 A – E; Lin et al. 2019: fig. 15 f – h), but it is distinguished by having the spermathecae pointing laterally at the centre (Fig. 6 A), not pointing towards the epigastric furrow in S. shoukaensis (Lin et al. 2019: fig. 15 f), and the copulatory ducts form a broad loop in ventral view (Fig. 6 A), rather than a narrow loop in S. shoukaensis (Lin et al. 2019: fig. 15 f). Description. Male (holotype, Fig. 10 H, I): total length: 3.12. Carapace 1.44 long, 1.17 wide, yellow, cephalic lobe 0.65 high with many microsetae; sulci present below the anterior eye row; fovea, cervical and radial grooves distinct. Clypeus 0.46 high. Chelicerae with 5 promarginal and 4 retromarginal teeth. AER strongly recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.07, ALE 0.06, PME 0.07, PLE 0.07, AME – AME 0.06, PME – PME 0.08, AME – PME 0.08, AME – ALE 0.03, PME – PLE 0.03, ALE – ALE 0.27, PLE – PLE 0.32, ALE – PLE 0.02. Length of legs: I 4.84 (1.43, 1.67, 1.05, 0.69), II 5.35 (1.51, 1.86, 1.40, 0.58), III 4.44 (1.24, 1.38, 1.30, 0.52), IV 4.95 (1.37, 1.63, 1.33, 0.62). Leg II longer than I. TmI 0.34. Tibial spine formula: 2-2 - 2 - 2. Abdomen 1.73 long, 1.13 wide, oval, pale, greenish-grey pattern followed by five transverse chevrons, ventral side greyish-pale. Pedipalp (holotype, Fig. 5 A – D). Patella 2 / 3 length of tibia, ventrally grooved. Tibia long, with 2 retrolateral and 1 dorsal trichobothria, with long, thick spines medially. Paracymbium U-shaped, distal arm covers more than half of proximal part in retrolateral view, tip tapering. Tegulum extending retrolaterally, with membranous protegulum. Distal suprategular apophysis disc-shaped, apically tapering. Radix with large, conspicuous anterior radical scaly part; anterior radical process membranous; lateral extension of radix slightly curved, ventrally grooved, wrapping embolus; tailpiece triangular, with pointed end; median membrane present; embolus sclerotised, arc-shaped, terminal part ends in tip of lateral extension of radix. Female (paratype, Fig. 10 J): total length: 3.71. Carapace 1.35 long, 1.05 wide. Clypeus 0.28 high. Chelicerae with 6 promarginal and 5 retromarginal teeth. AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.07, ALE 0.07, PME 0.07, PLE 0.08, AME – AME 0.03, PME – PME 0.07, AME – PME 0.07, AME – ALE 0.02, PME – PLE 0.03, ALE – ALE 0.29, PLE – PLE 0.35, ALE – PLE 0.02. Length of legs: I 5.14 (1.39, 1.73, 1.33, 0.69), II 5.26 (1.43, 1.73, 1.39, 0.71), III 3.92 (1.17, 1.19, 1.03, 0.53), IV 4.88 (1.38, 1.48, 1.33, 0.69). TmI 0.23. Abdomen 2.54 long, 2.04 wide. All other morphological characters same as in the male. Epigyne (Fig. 6 A – E). Epigynal plate wider than long. Ventral plate not extended posteriorly. Dorsal plate visible in ventral view, posterior margin with median depression. Copulatory openings present anteriorly. Vulva: copulatory ducts forming 2 broad loops before entering spermathecae. Spermathecae globular, dorso-laterally located, separated by more than twice their diameter; fertilisation ducts large, mesally extending. Distribution. Known only from the type locality (Fig. 11).