Alexarasniidae, Gorochov, 2011

ARISTOV, DANIIL S. & STOROZHENKO, SERGEY YU., 2021, A new genus of the family Alexarasniidae (Insecta: Embiida) from the Triassic of Kyrgyzstan, Palaeoentomology 4 (5), pp. 433-435 : 433-434

Key to taxa of Alexarasniidae (based on forewings)

1. CuA with 6–8 branches almost reaching wing apex; several posterior CuA branches looped, forming wavy ambient vein distant from wing margin and far from reaching wing apex (subfamily Alexarasniinae )........................................2

- CuA with 3–4 branches far from reaching wing apex; all CuA branches connected by smooth ambient vein running closely parallel to wing margin up to wing apex (subfamily Nestorembiinae ).................................................................4

2. Wing membrane irregularly wrinkled; apical wing onefourth dark; Sc proximally nearer to C than R, distally nearer to R than to C (genus Nikolembia ). Anterior margin of wing straight (see Shcherbakov, 2015: fig. 7).................. ........................... Nikolembia kusnezovi Shcherbakov, 2015

- Wing membrane transversely wrinkled; suffused except for base of preradial area; Sc proximally equidistant from C and R, distally nearer to C than to R (genus Alexarasnia )........3

3. Anterior margin of wing straight; CuA branches arranging irregularly (see Gorochov, 2011: fig. 1)................................ .................................... Alexarasnia rossica Gorochov, 2011

- Anterior margin of forewing convex; CuA branches forming a comb oriented to posterior margin of wing (see Aristov, 2017: fig. 2e)........... Alexarasnia limbata Aristov, 2017

4. RS and MA simple (genus Palaeomesorthopteron ). MP simple; CuA with three branches (see Aristov et al., 2011: fig. 1b).............................................. Palaeomesorthopteron pullus Aristov, Grauvogel-Stamm et Marchal-Papier, 2011

- RS with 2–4 branches, MA bifurcated................................5

5. MP desclerotized near middle; RS forming a long fusion (anastomosis) with MA. MP simple; CuA with four branches ( Fig. 1 ) ( Madygembia gen. nov.)...................................... ........................................... Madygembia rasnitsyni sp. nov.

- MP sclerotized along the full length; RS not fused with MA or basal branch of RS connected to MA by a long S-shaped crossvein (Genus Nestorembia Shcherbakov, 2015 )..........6

6. MA and MP with two branches; CuA with four branches (see Shcherbakov, 2015: fig. 13)........................................... ........................ Nestorembia novojilovi Shcherbakov, 2015

- MA and MP simple; CuA with three branches (see Aristov, 2017: fig. 2d)....... Nestorembia shcherbakovi Aristov, 2017

Figures

FIGURE 1. Madygembia rasnitsyni gen et sp. nov., forewing. A, Photograph of holotype. B, Sketch drawing of holotype. Scale bars = 3 mm.