Holcoptera rasnitsyni, Ponomarenko & Fedorenko & Bashkuev, 2022

Ponomarenko, A. G., Fedorenko, D. N. & Bashkuev, A. S., 2022, A new species of the beetle genus Holcoptera (Coleoptera: Coptoclavidae) from the Upper Triassic of east Ukraine, Russian Entomological Journal 31 (2), pp. 128-131 : 130-131

Holcoptera rasnitsyni

Ponomarenko et Fedorenko, sp.n.

Figs 1–5 .

MATERIAL. Holotype: PIN 3320 /204a±, imprint of incomplete beetle with carbonized organic matter, head, thorax, elytra and hind wings. Paratypes: PIN 3320 /113a± ( Figs 3–4 ), 3320/205a, incomplete beetles; 3320/206a, isolated elytron ( Fig. 5 ) .

LOCALITY AND HORIZON. Ukraine, Kharkov Region, Izyum District, the right bank of the Bereka River (tributary of the Seversky Donets River), 3 km north of the Velikaya Kamyshevakha village, Dolgy Jar ravine, Garazhovka locality; Upper Triassic, upper Carnian–lower Norian, Protopivka Formation.

DIAGNOSIS.The new species has the palest elytra among its congeners, with the external pale field occupying about 2/ 5 of the elytron width.

DESCRIPTION. Body oval, about twice as long as wide. Elytra pale, each with four, dark, longitudinal stripes in inner three fifths; these stripes subequally distant inter se; sutural stripe curved slightly laterad along apical margin; outer three reaching neither base nor apex.

Head about as long as wide. Eyes small and round. Pronotum wider than long. Profemur 2.3 times as long as wide. Protibia slender, curved, slightly longer than femur. Metanotum heavily sclerotized, twice as wide as long. Elytra subconvex, with apices widely rounded, less so at sutural angle.

Wings, holotype PIN, No. 3320/204a ( Figs. 1–2 ). Two almost completely folded hind wings visible, with apex of right wing somewhat unfolded; no distinct folds. Two longitudinal wing axes located in basal part of hind wing. Costal bar (cb = C+ScA+ScP+ R) distinctly and densely cross-striat- ed, consisting of strong vein C+ScA+ScP and barely detectable radial vein ( R), which is narrow and desclerotized distally. Cubital bar (Cu–CuA) broken into fragments, entire in distal half only, distally extended into large, well-defined, slightly transverse oblongum cell. Cubital joint at respective pivot on CuA proximal in position, so that CuA is abruptly geniculate at considerable distance from oblongum cell in both folded wings. Median bar (M– MP) not visible except small distal section apparently retained in form of vein ‘ y ’ in left hind wing .

Clavus and jugal lobe with few veins, broken and shifted basad, two vein fragments being only detectable: (1) CuP without apical section and (2) fragment of clavus “skeleton” with remains of first and second anal cells. Distinct line ‘ z ’ on the imprint apparently represents no vein, but posterobasal wing margin or jugal fold.

Venation of central region of wing hardly detectable. Region around first radial cell and probably also inner borders of carpal cell and first radial cell only traceable. This border is represented by vein x1 identifiable as either base of RP or complex vein RP–MA. Vein x2 looking like direct extension of vein x1 caudad, suggesting that x1–x2 may be simple vein. Yet, attribution of x2 to left wing CuA 1 appears more appropriate.

Pterostigma and almost all veins are recognizable in anterior part of unfolded wing apex frontal to longitudinal axial fold. Radial cell apparently partly incorporated in complex pterostigma. Caudal and basal borders of this cell invisible, except for distal portion of radial cell limited by crossvein (r2).

MEASUREMENTS. Elytron length 5.0–6.0 mm, elytron width 1.7–2.5 mm.

REMARKS. The described hind wing is extremely similar to another unfolded wing of a coptoclavid beetle [ Fedorenko, 2014]. It matches well the wing ground plan of Adephaga , notably Hydradephaga, virtually in all details. Only two features are worthy of note. Firstly, the large and elliptic oblongum cell is peculiar to nearly all Recent Hydradephaga. Secondly, the cubital joint is proximal, which has been observed in the most primitive representatives ( Gyrinidae , Haliplidae ) of Hydradephaga.

ETYMOLOGY. Named in honor of Alexandr Rasnitsyn.

Acknowledgments. We are grateful to two anonymous reviewers for their helpful comments. Many thanks to Anna Ponomarenko and Roman Rakitov for help in preparing the manuscript. The research was partly supported by the Russian Science Foundation, project No. 21-14-00284.

Competing interests. The authors declare no competing interests.

Figures

Fig. 1. Holcoptera rasnitsyni, sp.n.: holotype PIN 3320/204a. Scale bar: 2.0 mm. Рис. 1. Holcoptera rasnitsyni, sp.n.: голотип ПИН 3320/204a. МасШтаб: 2,0 мм.

Fig. 2. Holcoptera rasnitsyni, sp.n.: holotype PIN 3320/204a, drawing of wings. Abbreviations: 1r — 1st radial cell; AAP — vein AA 3a” +(AA 3b +(AA 4 +AP 1+2 )); cb — costal bar; cbz — costal bending zone; o — oblongum cell; pst — pterostigma; rc — radial cell; x1, x2, y — veins; z — posterobasal margin of folded wing (jugal fold). Scale bar: 1.0 mm. Рис. 2. Holcoptera rasnitsyni, sp.n.: голотип ПИН 3320/204a, прорисовка крыльев. ОбоЗначениЯ: 1r — 1-Я радиальнаЯ Ячейка; AAP — жилка AA 3a” +(AA3b+(AA 4 +AP 1+2 )); cb — костальнаЯ ось; cbz — Зона костального иЗгиба; o — продолговатаЯ Ячейка; pst — птеростигма; rc — радиальнаЯ Ячейка; x1, x2, y — жилки; z — постеробаЗальный край сложенного крыла (югальнаЯ складка). МасШтаб: 1,0 мм.

Figs 3–5. Holcoptera rasnitsyni, sp.n.: 3–4 — paratype PIN 3320/113a, photo and drawing (solid line — elytra, dashed line — wings, dotted line — metanotum); 5 — Paratype PIN 3320/206a. Scale bars: 2.0 mm. Рис. 3–5. Holcoptera rasnitsyni, sp.n.: 3–4 — паратип PIN 3320/113a, фотографиЯ и прорисовка (сплоШнаЯ линиЯ — контуры надкрылий, пунктирнаЯ линиЯ — крыльЯ, точечнаЯ линиЯ — Заднеспинка); 5 — паратип PIN 3320/206a. МасШтаб: 2,0 мм.