Animalia Araneae Oonopidae TongYanfengBianDongjuLiShuqiangThree new species of the genus Ischnothyreus Simon, 1893 and the discovery of the male of I.linzhiensis Hu, 2001 from Tibet, China (Araneae, Oonopidae)Zookeys09032023115211913110.3897/zookeys.1152.100341 6489A94F-F7B5-5B9B-9BA6-3309BA106BFB Ischnothyreus pome https://zoobank.org/89199E5A-66CB-4CA0-8396-6000B96A81EA sp. nov.Figs 4D–F, 6A–L, 7A–IType material.

Holotype ♂ (SYNU-526): China, Tibet, Nyingchi, Pome County, road to Metok County, 80 K; 29°39.897'N, 95°29.963'E; 2140±5 m; 10.VIII.2013; Qi Cao leg. Paratypes 2♂, 3♀ (SYNU-527-531): same data as for holotype.

Diagnosis.

Females of the new species are similar to those of I.jianglangi Tong & Li, 2020 in having the large, chestnut-shaped structure of the endogyne, but can be distinguished by the simple winding duct of the endogyne (Fig. 7H, I) vs. the complex winding duct (see Tong et al. 2020: fig. 17B). Males of the new species are similar to those of I.yunlong Tong & Li, 2021 in having the large flag-like sclerotized process of the cheliceral fang, but can be distinguished by the fused abdominal dorsal and epigastric scuta (Fig. 6C) vs. unfused (see Huang et al. 2021: fig. 1E), and by lacking the dorsal protuberance on the distal end of the bulb (Fig. 4D, E) vs. with dorsal protuberance (see Huang et al. 2021: fig. 2J).

10.3897/zookeys.1152.100341.figure6CB506222-14C7-55F0-8BF8-44F9E6FE65A5

Ischnothyreuspome sp. nov., male holotype A–C habitus in dorsal, ventral and lateral views (arrow shows the fused scuta) D–F prosoma, dorsal, ventral and anterior views G–I left chelicera, anterior, lateral and posterior views J–L left palp, prolateral, dorsal and retrolateral views. Abbreviations: flp = flag-like process; rlp = ridge-like protuberance; stp = strong, tooth-like projection; vp = ventral projection. Scale bars: 0.4 mm (A–F); 0.1 mm (G–L).

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10.3897/zookeys.1152.100341.figure76AD18E1E-1233-5BAC-A18C-29AF36391C0B

Ischnothyreuspome sp. nov., female paratype A–C habitus in dorsal, ventral and lateral views D epigastric region, ventral view E–G prosoma, dorsal, ventral and anterior views H, I endogyne, ventral and dorsal views (cleared in lactic acid). Abbreviations: a = apodeme; css = chestnut-shaped structure; wd = winding duct. Scale bars: 0.4 mm (A–C, E–G); 0.2 mm (D, H, I).

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Description.

Male (holotype). Body: habitus as in Fig. 6A–C; body length 1.58. Carapace: 0.84 long, 0.69 wide; yellow, oval in dorsal view, with brown egg-shaped patches behind eyes, pars cephalica strongly elevated in lateral view, surface of elevated portion of pars cephalica smooth, sides finely reticulate, lateral margin straight, smooth (Fig. 6D). Clypeus: straight in frontal view, ALE separated from edge of carapace by 1.4× of their diameter (Fig. 6F). Eyes: ALE largest, ALE circular, PME squared, PLE oval; posterior eye row recurved from above; ALE touching, ALE-PLE touching (Fig. 6D, F). Sternum: as long as wide, pale orange (Fig. 6E). Mouthparts: chelicerae, endites, and labium yellow; chelicerae straight, with ridge-like protuberance at anterior face, base of fangs with large flag-like sclerotized process, fang groove with a few small and two larger denticles (Figs 4F, 6G–I); anteromedian tip of endites with one strong, tooth-like projection (Fig. 6E). Abdomen: 0.74 long, 0.46 wide; dorsal scutum well sclerotized, dark brown, covering 3/5 of abdomen width and approximately 2/3 of abdomen length, fused to epigastric scutum (arrow in Fig. 6C); postgastric scutum covering ~ 5/6 of abdomen length. Legs: pale orange, femur I with two prolateral spines, tibia I with four pairs, metatarsus I with two pairs of long ventral spines. Leg II spination similar to leg I, except femur with only one prolateral spine. Legs III and IV spineless. Palp: trochanter with ventral projection; bulb without small ventral protuberance, distal end of bulb stout, with needle-like membrane and broad leaf-like projection (Figs 4D, E, 6J–L).

Female (paratype, SYNU-529). Same as male except as noted. Body: habitus as in Fig. 7A–C; body length 1.64. Carapace: 0.77 long, 0.67 wide. Mouthparts: chelicerae and endites unmodified. Abdomen: 0.88 long, 0.65 wide; dorsal scutum very small; epigastric scutum well sclerotized, orange; postgastric scutum widely hexagonal, only around epigastric furrow. Endogyne: winding duct simple, with anterior portion straight, strongly convoluted only in posterior section, ending in large, chestnut-shaped structure (Fig. 7H, I).

Etymology.

The specific name is a noun in apposition taken from the type locality.

Distribution.

Known only from the type locality.

10.3897/zookeys.1152.100341.figure4650F7C7E-E21F-531A-BA48-78A0D717E879

Ischnothyreuslinzhiensis Hu, 2001, male A–CSEM; Ischnothyreuspome sp. nov., male holotype D–FSEMA, E left palp, prolateral view B, D distal end of bulb, prolateral view C, F left chelicerae, anterior and posterior views. Abbreviations: ca = conical apophysis; dm = dorsal membrane; flp = flag-like process; llp = leaf-like projection; nlm = needle-like membrane. Scale bars: 0.1 mm (A, C, E, F); 0.05 mm (B, D).

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TongYLiSBianD (2020) Taxonomic study of the genus Ischnothyreus Simon, 1893 from Myanmar (Araneae, Oonopidae).ZooKeys993: 126. https://doi.org/10.3897/zookeys.993.57676HuangYTongYBianDLiS (2021) One new species of the genus Ischnothyreus Simon, 1893 and re-description of I.yueluensis Yin & Wang, 1984 from China (Araneae, Oonopidae). Biodiversity Data Journal 9: e66843. [11 pp] https://doi.org/10.3897/BDJ.9.e66843