Permeca chaohuensis, LIAN & CAI & HUANG, 2022

LIAN, XIN-NENG, CAI, CHEN‑YANG & HUANG, DI-YING, 2022, The earliest known species of Permeca (Insecta, Mecoptera, Permochoristidae) from the late Guadalupian Yinping Formation of China, Palaeoentomology 5 (4), pp. 395-399 : 396-397

Permeca chaohuensis sp. nov.

( Fig. 1 )

Material. Holotype, NIPG200025 ( Fig. 1 ), a forewing with its base not preserved. Length 2.9 mm (as preserved), width 1.2 mm.

Etymology. The specific epithet is derived from the type locality, Chaohu City.

Diagnosis. Forewing small, costal area moderately broad, apex of Sc straight, R 1 straight, and opening of Rs 1+2 and M 4a+b broad.

Type locality and horizon. Yinping mountain , Houdong Village, Chaohu City, Anhui Province, China; Yinping Formation, late Capitanian.

Description. Forewing, relatively small, wing apex slightly pointed, widest at apex of R 1; Sc 2-branched, with a short and oblique Sc 2, Sc runs parallel to costa before fork of Sc 1+2, and then broadens, and tilts to costa from point that connects cross-vein sc-r 1, apex of Sc 1 slightly beyond fork of Rs 3+4, and just entering margin of pterostigma; R 1 straight and robust, entering pterostigma; pterostigma elongate, lower margin demarcated by a vein-like boundary; Rs with 4 branches: stem Rs 1+2 length 1.0 mm, stem Rs 3+4 length 0.4 mm, stem Rs 1+2 about 2.5 times as long as stem Rs 3+4, opening of Rs 1+2 broad; M with 5 branches: stem M 1+2 length 1.0 mm, stem M 3+4 length 0.3 mm, stem M 1+2 ca. 3 times as long as stem M 3+4; M 4 bifurcated into two branches, stem M 4a+b sharply changed its direction at where the connected point with crossvein m-cua, opening of M 4a+b broad, vein of fork of M faint; CuA simple, sinuous apically, CuA base nearly horizontal, M 5 short and slightly oblique; CuP simple and apically curved downward to wing margin; two A detected, A 1 and A 2 both curved downward to wing margin apically; some cross-veins faint, a possible cross-vein connecting base of Rs 2 and Rs 3, Rs 4 and M 1, M 2 and M 3.

Remarks. The new species, Permeca chaohuensis sp. nov., is very similar to P. pygmaea ( Fig. 2D ), but it differs from the latter by the following characters: 1) costal area broader; 2) apex of Sc straight rather than sinuous, Sc 2 much longer and the fork of Sc 1+2 much closer to the fork of R 1 + Rs; 3) R 1 straight rather than sinuous, Rs 2 tilt downward instead of upward; and 4) the openings of Rs 1+2 and M 4a+b are broader. It can be readily distinguished from the type species of Permeca , P. tatarica ( Fig. 2B ), by its smaller wing size that is nearly half of the latter (width 1.2 mm vs. 2.0 mm), absence of colour patterns, Sc shorter (terminated only slightly passing the fork of Rs 3+4 vs. passed the fork of Rs 1+2), the openings of Rs 1+2 and M 4a+b are broad, stem M 4a+b sharply bent, and CuA base nearly horizontal instead of oblique. It differs from P. media ( Fig. 2C ) by its broader wing, broader costal area, shorter Sc (terminated just passing the fork of Rs 3+4 vs. terminated near the fork of Rs 1+2) and Sc terminal straight, R 1 straight, R 2 tilted downward, and CuA base nearly horizontal.

Figures

FIGURE 1. Permeca chaohuensis sp. nov., holotype NIGP200025, Yinping Formation at Chaohu City. A, Scanning electron microscopy (SEM) image. B, Forewing photo was taken under vertical reflected light. C, Line drawing. Scale bars represent 1 mm.

FIGURE 2. Comparison of the four species of Permeca. A, P. chaohuensis sp. nov. B, P. tatarica Novokshonov, 1995, redrawn based on Novokshonov (1995). C, P. media Bashkuev, 2013, redrawn based on Aristov et al. (2013). D, P. pygmaea Bashkuev, 2013, redrawn based on Aristov et al. (2013). All wings are at the same scale bar of 1 mm.