Vyazonemoura storozhenkoi Sinitshenkova & Yan, 2025

Sinitshenkova, Nina D. & Yan, Evgeny V., 2025, The unusual stonefly wing from the Upper Permian of the Orenburg Region of Russia: a new genus and species Vyazonemoura storozhenkoi gen. et sp. nov. (Insecta: Plecoptera, Palaeonemouridae), Zootaxa 5715 (1), pp. 441-445 : 443-444

Vyazonemoura storozhenkoi Sinitshenkova & Yan , sp. nov.

( Fig. 2 )

Type material. Holotype 5516/228: positive imprint of the complete forewing ( PIN RAS).

Horizon and locality. Upper Permian , Severodvinian Stage, Vyazovka Fm. The locality is Vyazovka-1, in the vicinity of the village of Vyazovka, Orenburg Region, Russia. GPS: 51.7246730°N, 55.833153°E .

Diagnosis. As for the genus.

Description. Length of forewing ( holotype): 6.5 mm; its greatest width: 1.3 mm. The costal field of the forewing is very narrow, within which at least three crossveins can be distinguished. The oblique crossvein in the pterostigmal region is located in the apical quarter of the wing. SC is slightly curved at the base and flows into R in the distal third of the wing length; c-sc flows into C noticeably basal to the apex of SC. RS departs from R in the basal quarter of the wing length; there are two r-rs crossveins. The distal r-rs departs from R basal to the apex of SC, and the second flows into RS basal to rs-m. The petiole of RS is three times shorter than its branches; rs-m departs from RS basal to r-rs and flows into MA noticeably distal to the M fork; m-cu departs from MP distal to the fork of M and flows into CuA basal to its first fork; in the medial field there are four crossveins. CuA is pectinate posteriorly with four short branches. CuP is short and flows into the wing margin distal to the point of departure of RS from R.

Remarks. The unusual proportions of the V. storozhenkoi ’s wing—very narrow relative to its length—suggest that it was deformed after burial by sediment movement. Such phenomena are observed in some localities. The strong distortion of wing proportions is especially pronounced at the Dzhayloucho locality, Kyrgyzstan, where the Madygen Formation deposits are dated to the Middle-Upper Triassic. Stretching of the wings in different directions is noted in stoneflies ( Sinitshenkova 1987), in hymenoptera Symphyta ( Rasnitsyn 1969: 10), and in beetles ( Ponomarenko 1969: 5–7). The deformation of fossil insects at Dzhayloucho is apparently due to compression and stretching of the host rock. In Vyazovka, no similar deformation was noted for any remains of stoneflies, dragonflies ( Felker 2020), mecopterans ( Bashkuev 2022), or caddisflies ( Sukatsheva & Sinitshenkova 2025) described from here; apparently, there is no reason to assume a distortion of the natural dimensions of the wing of V. storozhenkoi gen. et sp. nov.

Etymology. The new species is named in honor of the paleoentomologist Sergey Storozhenko (Vladivostok, Russia).

Figures

FIGURE 2. Vyazonemoura storozhenkoi Sinitshenkiva & Yan, gen. et sp. nov., the holotype 5516/228 photograph (A) and interpretative line drawing (B). Scale bars = 1.0 mm.