Gomphaeschna carinthiae, Schädel, Mario & Lechner, Thomas S., 2017

Schädel, Mario & Lechner, Thomas S., 2017, Two new dragonflies (Odonata: Anisoptera) from the Miocene of Carinthia (Austria), Zootaxa 4243 (1), pp. 153-164 : 159-162

Gomphaeschna carinthiae sp. nov.

Figures 3–5

Holotype. UMJG &P 211472, collection of the Universalmuseum Joanneum , Graz, Austria.

Diagnosis. The specimen differs from all Recent and fossil gomphaeschnid species in the broad space between Rspl and IR2 and the distinct oblique crossvein that connects these two veins.

Description Graz. The fossil was split during its excavation and is now present in two halves. Both halves show mostly the same but mirrored parts of the venation. Almost the complete wing is preserved and visible. The preservation lacks only the proximal posterior part of the wing. The tip of the wing dips into the sediment of plate A whereas the proximal anterior edge of the wing dips in plate B.

Total length 28.4 mm; total width 9.6 mm. Secondary antenodal crossveins not aligned. Pterostigma roughly parallel sided; 3.1 mm in proximodistal dimension and maximum 0.9 mm in anteroposterior dimension; proximal and distal margin oblique with an angle of 134° between RA and proximal margin and 135° between posterior margin and distal margin. Pterostigmal brace vein oblique in extension of proximal margin of pterostigma.

Preradial and interradial fields both with one row of cells.

Distalmost crossvein in antesubnodal space at level of junction between RP´and IR2. Distance between RP´–RP´´furca and subnodus 4.0 mm. Distinct 1.3 mm long oblique crossvein at distance of 9.8 mm from RP´–RP´´furca between IR2 and Rspl with an angle of 127° to proximal side of IR2. The part of Rspl proximal to the distinct IR2-Rspl crossvein is not preserved. At least five straight veins running from Rspl towards posterior wing margin.

RP2 slightly undulating with least distance to RP1 at level of the pterostigmal brace vein. One row of cells between RP1 and RP 2 in proximal part; two rows of cells from 13.5 mm distance to RP´-RP´´furca to distalmost preserved part.

Premedial field with one row of cells and with parallel boundaries; posterodistal part of premedial field not distinctly broader than rest.

At least four antefurcal crossveins between RP - and MA+.

Htc at least 3.8 mm long and 0.4 mm wide at half length of tcv; MA almost parallel to tcv and only curved in its distal part.

Discoidal triangle longitudinally stretched and divided by at least one secondary crossvein; basal side 1.7 mm; costal side 3.3 mm; posterodistal side 3.2 mm; posterodistal side (ddv) almost straight with a slight kink at the origin of the distinct Tspl. Tspl meets MP almost orthogonally.

Three rows of cells in basal part of postdiscoidal space. One intercalated vein in medial field. At least one intercalated vein or secondary branch of CuA´in antecubital field.

Preanal field with 3 cells on anterior side; anterior side width 3.1 mm. Anal field 1.2 mm wide and unicellular on anterior side, narrowing towards posterior wing margin. (AA´´& AP) concave on proximal side and approaching AA2b posteriorly.

CuP crossing 0.7 mm long and 1.4 mm proximal to anteroproximal angle of triangulum. Anterior side of subdiscoidal cell 1.4 mm long. PsA joins proximal side of triangulum 0.2 mm posterior to anteroproximal angle of triangulum.

Subtriangular cell with posterior side 1.6 mm; anterior side (PsA) 1.0 mm; distal side 1.5 mm. Posterior side of subtriangulum not joining posterior angle of triangulum; sdv distinct but short (> 0.1 mm).

Type locality and horizon. Claypit Schaßbach (46°47'53.32"N, 14°48'23.77"E), St. Andrä , Wolfsberg (district), Carinthia, Austria. Laminated siltstone of the lacustrine lower part of the Mühldorf Formation. Age late Early Miocene.

Etymology. The species name refers to the state of Carinthia (Kärnten) in Austria where the fossil was found.

Sex determination. The holotype is presumably the hind wing of a male specimen. The anal field is relatively narrow and unicellular in the basal part. Also (AA´´& AP) is concave on its proximal side and approaching the straight AA2b posteriorly. This could indicate an anal angle characteristic for male anisopterans that is not preserved in this fossil.

Phylogenetic affinities. The specimen can be clearly attributed to the suborder Anisoptera Selys, 1854 , by the strong expansion of the cubito-anal field and the presence of a discoidal triangle as well as a hypertriangle and a subtriangle ( Bechly 2007).

Aeshnoptera Bechly, 1996: space between RP1 and RP2 narrowed with only one row of cells to pterostigma; Rspl present ( Bechly 2003).

Aeshnomorpha Bechly, 2001: RP2 slightly undulating ( Bechly 2003).

Euaeshnida Bechly, 1996: RP2 and IR2 distinctly non-parallel ( Bechly 2003).

Gomphaeschnidae Tillyard & Fraser, 1940 : ‘cordulegastrid gap’ (distalmost part of the antesubnodal area without crossveins); no accessory crossveins between CuP-crossing and PsA in subdiscoidal cell; triangulum divided by one crossvein; hypertriangle unicellular ( Bechly et al. 2001; Bechly 2003).

Gomphaeschna Selys, 1871 : IR2 and Rspl more or less parallel; RP2 undulating; hind wing triangle with basal side longer than 1/2 costal side; cubito-anal space with 1 crossvein (CuP-crossing); Rspl with no distinct connection to wing margin ( Garrison et al. 2006).

No elongated paranal cell basal to anal loop in hind wing as in Gomphaeschnaoidini Bechly, 2001 ( Bechly et al. 2001).

Figures

FIGURE 3. Photograph of the hind wing fragment of Gomphaeschna carinthiae sp. nov., holotype UMJG & P 211472, plate A. The wingtip is covered with sediment.

FIGURE 4. Photograph of the hind wing fragment of Gomphaeschna carinthiae sp. nov., holotype UMJG & P 211472, plate B. The posterobasal area of the wing is covered with sediment.

FIGURE 5. Drawing of the hind wing fragment of Gomphaeschna carinthiae sp. nov., holotype UMJG & P 211472. The drawing involves features of both plates.