Litholingia longa, Khramov, Alexander V., 2012

Khramov, Alexander V., 2012, The new fossil lacewings of Grammolingiidae (Neuroptera) from the Jurassic of Central Asia and Mongolia, with notes on biogeography of the family, Zootaxa 3478, pp. 297-308 : 301-302

Litholingia longa sp. nov.

Description. Holotype. Forewing ( Fig. 4 ). Length 35 mm as preserved (estimated complete length 40 mm), width 11 mm (estimated width 12–13 mm). There are two rows of cells along entire length of the wing. Longitudinal vein b located between the stem of Rs and basal part of MP and fused with Rs near to origin MA from Rs. MP forked after origin MA from Rs. Distal part of MP2 deeply dichotomously branched. CuP pectinately branched, the first of its 4 branches forked. Branches of A1 connected by crossveins and forked.

Specimens PIN № 2389/526, № 3073/840, № 3073/842, № 3073/453, № 3073/447, № 3073/446, № 3073/448. Forewings ( Fig.5 ). They slightly vary in size and belong to wings of medium length (35–45 mm). Their costal area contains two rows of cells. All specimens have the distinct oblique or longitudinal vein b between the stem of Rs and the basal part of MP. In the most of specimens vein b fused with Rs at the point of the separation MA from Rs, but also could join it distally, as in the fragment PIN № 3073/453 ( Fig. 5 D). MP commonly forked slightly after the separation MA from Rs, but also could forked at the level of it (as in PIN 3073/448, Fig. 5 G). The anal area is preserved in specimen PIN № 2389/526 ( Fig. 5 A): A2 terminates by three short branches, A3 is a simple.

Type material. Holotype PIN № 1526/1, an incomplete forewing. Kyrgyzstan: Batken Province, Batken district on the border with Tajikistan; Sai-Sagul locality, upper Lower Jurassic – lower Middle Jurassic.

Other material examined. Specimens PIN № 2389/526, № 3073/840, № 3073/842, № 3073/453, № 3073/ 447, № 3073/446, № 3073/448, all are fragments of the forewing proximal part. Same locality.

Etymology. From the Latin word longus, - a, meaning “long”.

Comments. The holotype belongs to Litholingia , because A1 terminates on the posterior margin after the separation Rs1 from Rs, and CuA forked after the bifurcation of CuP. The imprint is slightly crumpled in transverse direction (R1 is not visible, the area of CuA is deformed). L. longa differs from other four species of Litholingia ( L. rhora Ren, 2002 , L. eumorpha Ren, 2002 , L. polychotoma Ren, 2002 and L. ptesa Shi et al., 2011 ) by the pectinate CuP. Similar structure of CuP is observed in the forewing of Leptolingia calonervis Shi et al., 2011 , whose CuP also has 4 branches. It corroborates the assumption of Shi et al. (2011), that CuP of Grammolingiidae might be not only dichotomously branched, but also slightly pectinately branched.

The vein b, which is apparent in forewings of L. longa , may be interpreted as the remnant of the basal part of media, which anterior branch (MA) in the very beginning falls into Rs and immediately after that separates from it, like branches of Rs (consequently, the first vein, that separates from Rs is MA and only the second is Rs1) ( Martynov 1928). The remnant of the b asal part of media (vein b) is usually visible only in hind wings ( Carpenter 1943). However, other specialists suppose, that b is only a modified crossvein ( Comstock 1918, Tjeder 1957). In any case, the presence of this vein in forewings of L. longa is an important peculiarity.

The comparison of seven described specimens ( Fig. 5 ) allows making conclusion about the individual variability of wings of Grammolingiidae , if these specimens really belong to the same species.

Figures

FIGURE 4. Litholingia longa sp. nov., Sai Sagul locality, Kyrgyzstan, upper Lower Jurassic – lower Middle Jurassic. (A). The photograph of the proximal part of the forewing. Holotype, PIN № 1526 / 1. (B) The drawing of the holotype, PIN № 1526 / 1. Scale bar represents 5 mm.

FIGURE 5. Litholingia longa sp. nov., Sai Sagul locality, Kyrgyzstan, upper Lower Jurassic – lower Middle Jurassic. The drawings of proximal parts of the forewings. A, PIN № 2389 / 526; B, PIN № 3073 / 840; C, PIN № 3073 / 842; D, PIN № 3073 / 453; E, PIN № 3073 / 447; F, PIN 3073 / 446; G, PIN 3073 / 448. Scale bar represents 5 mm.