Ischnothyreus metok, 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 metok sp. nov.

Fig. 5A-I

Type material.

Holotype ♀ (SYNU-525): China, Tibet, Nyingchi, Metok County, Metok Town, Countryside Tour, 29°19.087'N, 95°18.876'E, 1280 ± 5 m, 4.VIII.2013, Qi Cao leg.

Diagnosis.

The new species is similar to I. comicus Edward & Harvey, 2014 in the size of the abdominal scuta, but can be distinguished by the semicircle-shaped depression of the endogyne (Fig. 5H ) vs. a smile-shaped depression (see Edward and Harvey 2014: figs 13I, 14F).

Description.

Female (holotype). Body: habitus as in Fig. 5A-C ; body length 1.64. Carapace: 0.77 long, 0.67 wide; dark brown, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, surface of elevated portion of pars cephalica finely reticulate, sides strongly reticulate, lateral margin straight, smooth (Fig. 5E ). Clypeus: straight in frontal view, ALE separated from edge of carapace by less than their radius (Fig. 5G ). Eyes: ALE largest, ALE circular, PME squared, PLE oval; posterior eye row procurved from above; ALE separated by less than their radius, ALE-PLE touching (Fig. 5E, G ). Sternum: longer than wide, pale orange (Fig. 5F ). Mouthparts: chelicerae, endites and labium yellow; chelicerae and endites unmodified. Abdomen: 0.88 long, 0.65 wide; dorsal scutum well sclerotized, dark brown, covering 1/3 of abdomen width and approximately 1/3 of abdomen length, not fused to epigastric scutum; epigastric scutum well sclerotized, yellow; postgastric scutum widely hexagonal. Legs: 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: with large, semicircle-shaped depression; winding duct complex, strongly convoluted (Fig. 5H, I ).

Male. Unknown.

Etymology.

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

Distribution.

Known only from the type locality.

Figures

Figure 5. Ischnothyreus metok 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; ssd = semicircle-shaped depression; wd = winding duct. Scale bars: 0.4 mm (A-C, E-G); 0.2 mm (D, H, I).