Ischnothyreus caoqii, Tong & Bian & Li, 2023

Tong, Yanfeng, Bian, Dongju & Li, Shuqiang, 2023, Three new species of the genus Ischnothyreus Simon, 1893 and the discovery of the male of I. linzhiensis Hu, 2001 from Tibet, China (Araneae, Oonopidae), ZooKeys 1152, pp. 119-131 : 119

Ischnothyreus caoqii sp. nov.

Fig. 1A-I

Type material.

Holotype ♀ (SYNU-508): 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.

Diagnosis.

The new species is similar to I. jianglangi Tong & Li, 2020 in the size of the abdominal scuta, but can be distinguished by the large, semicirculared structure of the endogyne and the simple winding duct (Fig. 1H, I ) vs. a triangular structure and a complex winding duct (see Tong et al. 2020: fig. 17A, B).

Description.

Female (holotype). Body: habitus as in Fig. 1A-C ; body length 1.96. Carapace: 0.94 long, 0.82 wide; brownish, with a yellowish center, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, surface of elevated portion of pars cephalica smooth, sides finely reticulate, lateral margin straight, smooth (Fig. 1E ). Clypeus: straight in frontal view, ALE separated from edge of carapace by less than radius (Fig. 1G ). Eyes: ALE largest, ALE circular, PME squared, PLE oval; posterior eye row recurved from above; ALE touching, ALE-PLE touching (Fig. 1E, G ). Sternum: longer than wide, pale orange (Fig. 1F ). Mouthparts: chelicerae, endites, and labium orange; chelicerae and endites unmodified. Abdomen: 1.05 long, 0.73 wide; dorsal scutum well sclerotized, pale orange, covering 1/3 of abdomen width and approximately 1/3 of abdomen length; epigastric scutum well sclerotized, pale orange; postgastric scutum hexagonal. 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. Endogyne: winding duct complex, strongly convoluted, ending in semicircle-shaped structure (Fig. 1H, I ).

Male. Unknown.

Etymology.

The species is named after Mr. Qi Cao, the collector of the type specimens; noun in genitive case.

Distribution.

Known only from the type locality.

Figures

Figure 1. Ischnothyreus caoqii sp. nov., female holotype 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; sss = semicircle-shaped structure; wd = winding duct. Scale bars: 0.4 mm (A-C, E-G); 0.2 mm (D, H, I).