Guithone bethouxi, Zheng & Ren & Wang, 2016

Zheng, Bingyu, Ren, Dong & Wang, Yongjie, 2016, Earliest true moth lacewing from the Middle Jurassic of Inner Mongolia, China, Acta Palaeontologica Polonica 61 (4), pp. 847-851 : 849-850

Guithone bethouxi sp. nov.

Figs. 1–3 .

Etymology: In honour of Olivier Béthoux to acknowledge his sincere help to Bingyu Zheng.

Holotype: CNU-NEU-NN2015003P/C, a nearly completely preserved male specimen with clearly visible structures, and four overlapping, sub-complete wings, partially folded.

Type locality: Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China.

Type horizon: Jiulongshan Formation, Bathonian–Callovian boundary beds (165 Ma), Middle Jurassic.

Diagnosis.—Trichosors present along the anterior margin; humeral veinlet simple, not recurrent; costal crossveins sinuous at their base, with distal dichotomous forks (rarely trichotomous); Sc and R1 reaching the anterior margin separately; few crossveins in the radial sector; MP fork beyond the separation of MA from Rs.

Description.—Body: well preserved, ca. 14.5 mm long, robust, with few hairs on the surface; head hypognathous, concealed under pronotum, ca. 1.2 mm long; antennae not preserved; compound eyes large, as wide as the half of frons; ocelli absent; mandible stout, apical portion sharp; thorax stout, less hairy; scutums in mesoscutum nearly round on both sides; mesoscutum of similar size as metascutum; legs medium-sized (ca. 1.5 mm), covered by abundant setae; tarsal claws short, sharp, with arolium at base of each; abdomen stout. Gender masculine.

Forewing: slender, ca. 19.3 mm long and 5.2 mm wide as preserved; dense hairs along margin and veins. Trichosors distributed ( Fig. 1A 2 ) along the proximal half of anterior margin; nygmata not detected; costal area shrinking gradually from the base to apex (2.2 mm maximum width, 0.9 mm minimum width); humeral veinlet not recurrent ( Figs. 2A, B , 3A); costal cross-veins slightly sinuous at the base, and dichotomously forked distally (rarely trichotomous); Sc and R1 separated distally, reaching the anterior margin before wing apex ( Fig. 3B); subcostal space narrowed basad and broadened distad (possibly as a consequence of compression); Rs slightly zigzagged in distal portion, with 17 regularly pectinate branches; MA simple, and the divergence of MA close to the origin of Rs; MP forked beyond the divergence point of MA from Rs; MP2 only partly preserved, first fork near mid-length of wing; CuA simple; CuP pectinately branched; anal region well developed, A1–A3 each with 2–4 distal branches.

Hindwing: incompletely preserved, main veins hardly identifiable; trichosores not detected; frenulum well preserved, visible on both hindwings ( Fig. 1B ). Wing membrane tinged with irregular pale brown shades.

Figures

Fig. 1. Moth lacewing Guithone bethouxi gen. et sp. nov. holotype (CNU-NEU-NN2015003P/C) from Bathonian–Callovian boundary (Middle Jurassic) of Jiulongshan Formation of Daohugou, China. Photographs: dry-ethanol (A) and ethanol-ethanol (B) composites; detail (A ). tr, trichosors; f, frenulum.

Fig. 2. Moth lacewing Guithone bethouxi gen. et sp. nov. holo- type (CNU-NEU-NN2015003P/C) from Bathonian–Callovian boundary (Middle Jurassic) of Jiulongshan Formation of Dao- hugou, China. Line drawings of wing venation: left (A) and right (B) forewings, left (C) and right (D) hindwings.