Age, Diakonoff, 1982

Prokop, Jakub, Pecharová, Martina & Nel, André, 2016, New Cenozoic dragonflies from the Most Basin and Středohoří Complex volcanic area (Czech Republic, Germany), Journal of Natural History 50, pp. 2311-2326 : 2316-2317

cf. Aeshna sp.

( Figure 3 (a, b))

Material

SMMG Ku 398 (a nearly complete fore wing lacking base and parts along posterior margin, preserved in brown diatomite), collection of Senckenberg Naturhistorische Sammlungen Dresden, Saxony, Germany .

Age and outcrop

Early Oligocene (Rupelian – Chattian), Ústí Formation, Středohoří Complex, Kundratice near Litoměřice ( Figure 1 ), Czech Republic (see Kvaček and Walther 1998).

Description

A nearly complete fore wing, with only basal anterior area and parts along posterior wing margin missing; wing surface apparently hyaline; wing c. 52 mm long (assumed from fragment) and 17.5 mm wide; distance from estimated base to nodus c. 25.3 mm; distance from nodus to wing apex, c. 26.6 mm; nodus nearly midway between base and apex; distance from nodus to pterostigma 17.4 mm; distance from pterostigma to apex about 5.6 mm; pterostigma rather long, 4.0 mm long and 0.9 mm wide, covering approximately five cells; pterostigmal brace obliquely aligned with proximal side of pterostigma; 20 postnodal cross-veins, not well aligned with 16 visible subpostnodal cross-veins; 12 visible antenodal crossveins of first row between C and ScP not aligned with one visible corresponding antenodal cross-veins of second row between ScP and RA; hypertriangle crossed by three or more cross-veins; median space free, partly preserved; submedian space crossed by two cross-veins, subdiscoidal triangle twocelled; discoidal triangle elongate and divided into five small cells, its costal side being 6.6 mm long, distal side 5.9 mm long and proximal side 2.8 mm long; width of postdiscoidal area just behind discoidal triangle 3.4 mm, width along posterior wing margin 7.2 mm; three rows of cells in postdiscoidal area just distal of discoidal triangle; convex supplementary sector (trigonal planate) in postdiscoidal area, aligned with concave Mspl; Mspl well defined, undulated; two or three rows of cells between Mspl and MP and also between Mspl and MA; bulge in distal part of MA (‘ aeshnid bulla ’) apparently weaker than in Aeshna zlatkokvaceki sp. nov., but it is too poorly preserved to be accurately described; five preserved Bq cross-veins; oblique vein ‘ O ’ one cell distal of base of RP2; Rspl well defined and nearly straight; area between Rspl and IR2 with three rows of cells in its widest part; IR2 smoothly curved distally and asymmetrically forked 5.0 mm proximad of pterostigma, with three rows of cells between its branches; RP2 strongly curved posteriorly opposite proximal side of pterostigma; one row of cells between RP2 and anterior branch of IR2; IR1 nearly straight beginning just below proximal posterior edge of pterostigma; one row of cells between MP and CuAa in basal parts, but with about five or six along posterior wing margin; CuAa with circa six posterior branches directed towards posterior wing margin, but not preserved; cubitoanal area poorly preserved, but distinctly broad with about seven rows of cells below CuAa.

Figures

Figure 1. Map of Cenozoic dragonfly localities in the Krušné hory piedmont basins and volcanic areas. Abbreviations: I, Cheb and Sokolov basins; II, Most Basin; III, České středohoří Mts. and Doupovské hory Mts.; 1, Želénky near Duchcov; 2, Bílina mine; 3, Kundratice near Litoměřice; 4, Seifhennersdorf; 5, Libouš mine; 6, Jehličná near Sokolov; 7, Marie Majerová mine near Sokolov; 8, Pochlovice near Kynšperk n. Ohří.

Figure 3. cf. Aeshna sp. (Aeshnidae), (A) photograph of specimen SMMG Ku 398 (Senckenberg Naturhistorische Sammlungen Dresden coll., Germany), imprint only; (B) line drawing of fore wing. Scale bars represent 5 mm.