Ischnothyreus tadfane, Tong, Yanfeng & Li, Shuqiang, 2013

Tong, Yanfeng & Li, Shuqiang, 2013, Six new species of oonopid spiders from Champasak, Laos (Araneae, Oonopidae), Zootaxa 3709 (1), pp. 71-88 : 76

Ischnothyreus tadfane sp. nov.

Figure 4

Type material: Holotype: Female ( IZCAS AR 19388), Laos, Champasak Province, Tad Fane Resort, 15º10.944'N, 106º07.606'E, elevation 955 meters, November 21, 2012, leg. S. Li. Paratype: 1 female ( IZCAS AR 19408), same data as holotype.

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

Diagnosis: The new species is similar to I. fobor Kranz-Baltensperger, 2011 , but can be distinguished by the long dorsal scutum, the shape of the postepigastric scutum and the inverted-bell-shaped atrium in female genital area.

Description: Female (holotype). Body length 1.8; carapace 0.77 length, 0.68 width; abdomen 1.0 length, 0.6 width. Habitus as in Figs 4 A, B. Carapace: dorsally orange-brown, sides blackish brown, oval in dorsal view, pars cephalica slightly elevated in lateral view, surface and sides strongly reticulate ( Figs 4 C, D). Eyes: six, in one group, well developed, ALE largest, PME and PLE nearly equal sized; posterior eye row slightly procurved from above and front. Mouthparts ( Fig. 4 E): chelicerae slightly divergent, without prominent basal process. Anterior margin of labium not indented at middle. Anteromedian tip of endites unmodified ( Fig. 4 F). Abdomen: dorsal scutum and scutum above pedicel tube blackish brown. Pedicel tube short, unmodified, scutum extending far dorsal of pedicel. Book lung covers light, large, elliptical. Dorsal scutum covering about 2/3 of abdomen, about 4/5 of abdomen width. Postepigastric scutum not fused to epigastric scutum, with short posteriorly directed lateral apodemes ( Fig. 4 G). Leg formula: femur I with 2 prolateral and 1 small retrolateral spines, tibia I with 4 pairs, metatarsus I with 2 pairs of long ventral spines. Leg II spination is similar to leg I except femur with only 1 prolateral spine. Legs III and IV spineless. Genitalia: the posterior margin of the epigastric scutum is lined with numerous needle-like setae; at middle of anterior edge of the postepigastric scutum runs a dark, strongly winding tube (wt) posteriorly, ending in a inverted-bell-shaped atrium (iba) ( Figs 4 H–K).

Male: Unknown.

Distribution: Known only from the type locality.

Discussion: The species I. corollacous sp. nov. and I. tadfane sp. nov. were collected from the same locality, both species are only known from females at present. I. tadetu sp. nov., only known from males at present, was collected from a different locality. The species I. corollacous sp. nov. has a very short abdominal dorsal scutum, a slightly elevated pars cephalica and a very special spination on the legs (femur I with 3 prolateral and 2 small retrolateral spines, femur II with 2 prolateral and 1 small retrolateral spine). These characters suggest that I. corollacous sp. nov. and I. tadetu sp. nov. are not the same species. The species I. tadfane sp. nov. is different from I. tadetu sp. nov. because the former species has a very long abdominal dorsal scutum, relatively small eyes and dark brown color on the carapace and the abdomen.

Figures

FIGURE 4. Ischnothyreus tadfane sp. nov., female. A, B. Habitus, dorsal and lateral views; C – F. Prosoma, dorsal, lateral, anterior and ventral views; G. Abdomen, ventral view; H – K. Genitalia, ventral (H, J) and dorsal (I, K) views. Abbreviations: a, apodeme; iba, inverted-bell-shaped atrium; wt, winding tube. Scales: A, B = 0.4 mm; C – G = 0.2 mm; H, I = 0.1 mm; J, K = 0.05 mm.