Irura yarlungzangbo Wang, Mi, Li & Xu, 2024, sp. nov.

Irura yarlungzangbo sp. nov. Figs 9, 10, 47 Type material. Holotype ♀ (TRU - JS 0739), China: • Xizang Autonomous Region, Medog County, Beibeng Township, Deergong Village, Yarlung Zangbo National Nature Reserve (29°10.84'N, 95°8.67'E, ca 1670 m), 25. V. 2024, X. Q. Mi et al. leg. Paratypes • 1 ♂ 2 ♀ (TRU - JS 0740–0742), same data as for holotype. Etymology. The specific name refers to the Yarlung Zangbo National Nature Reserve, the type locality; noun in apposition. Diagnosis. The female of Irura yarlungzangbo sp. nov. resembles that of I. zhangae Gan, Wang & Peng, 2017 in having a similar epigyne, but can be easily distinguished by the anterior chamber of spermatheca (AS), ~ 1.3 × longer than wide (Fig. 10 B) vs ~ 2 × longer than wide (Gan et al. 2017: fig. 2 F, G, 3 D, E), and by the absence of an incision between copulatory openings (Fig. 10 A) vs having a square incision between copulatory openings (Gan et al. 2017: figs 2 F, G, 3 D, E). The male can be easily distinguished by the presence of dorsal cymbial extension (DCE), which bears several retromarginal spines (Fig. 9 B, C) vs absent in other congeners (see Metzner 2024). Description. Female (Fig. 10 A, B, D – G). Total length 3.78. Carapace 1.43 long, 1.65 wide. Abdomen 2.05 long, 1.65 wide. Eye sizes and interdistances: AME 0.38, ALE 0.22, PLE 0.19, AERW 1.31, PERW 1.55, EFL 0.74. Legs: I 3.28 (1.05, 0.75, 0.65, 0.48, 0.35), II 2.31 (0.75, 0.45, 0.45, 0.38, 0.28), III 2.02 (0.63, 0.35, 0.38, 0.38, 0.28), IV 2.49 (0.85, 0.43, 0.50, 0.43, 0.28). Carapace red-brown, covered with thin brown setae and pale scales, with pair of dark spots centrally on eye field. Chelicerae incised on base of anterior surface, with two promarginal teeth and one retromarginal fissidentate tooth with three cusps. Leg I robust, with two pairs of ventral spines on tibiae and metatarsi. Abdomen oval, dorsum mainly pale, with two pairs of anterior muscle depressions and medio-posterior shallow depressions surrounded by brown C-shaped stripes; venter with dark brown posterior half, and two pairs of pale yellow dotted lines. Epigyne (Fig. 10 A, B) ~ 1.65 × wider than long, weakly sclerotized; copulatory openings (CO) postero-marginally located, opened posterolaterally, separated by> 1 / 3 epigynal width; copulatory ducts (CD) thin, slightly curved proximally and distally, and connected to distal portions of junction ducts of spermathecae (JS); spermathecae (S) divided into oval anterior chamber (AS) and spherical posterior chamber (PS); fertilization ducts (FD) originating at antero-inner margins of anterior chamber of spermatheca. Male (Figs 9, 10 C, H). Total length 2.63. Carapace 1.29 long, 1.37 wide. Abdomen 1.41 long, 1.22 wide. Eye sizes and interdistances: AME 0.35, ALE 0.20, PLE 0.15, AERW 1.14, PERW 1.31, EFL 0.65. Legs: I 3.53 (1.05, 0.75, 0.78, 0.50, 0.45), II 2.34 (0.75, 0.43, 0.45, 0.43, 0.28), III 2.00 (0.63, 0.33, 0.38, 0.38, 0.28), IV missing. Carapace (Fig. 10 C) brown, covered with purplish gold scales. Chelicerae (Fig. 10 H) similar to that of female except retromarginal fissidentate tooth only with two cusps. Legs brown, mingled with green. Abdomen (Fig. 10 C) oval, dorsum mainly dark brown, covered with purplish gold scales, with pair of pale median patches and transverse, posterior, pale band; venter dark brown. Palp (Fig. 9 A – C): femur length / width ratio ca 2.72; patella ~ 1.6 × longer than wide in retrolateral view; tibia slightly longer than patella, with well-developed, lamellar retrolateral apophysis (RTA) and swollen dorsal process (DTP); cymbium ~ 2 × longer than wide, with weakly sclerotized retrolateral process (CP) partly covered by retrolateral tibial apophysis and with pointed end, and well developed, posteriorly extending dorsal extension (DCE) bearing several retromarginal spines; tegulum flat, oval; embolus (E) filiform, 1.2 × longer than tegulum, originating at ca 9 o’clock position. Distribution. Known only from the type locality in Xizang, China (Fig. 47).