AESHNIDAE, Rambur, 1842

CROWN AESHNIDAE View in CoL

Node Calibrated: (5) Crown Aeshnidae . This node represents crown Aeshnidae .

Species. Gomphaeschna inferna (Gomphaeschninae) Pritykina, 1977

Specimen. Hind wing without base, PIN 1989/ 1808 Paleontological Institute of the Academy of Science of Russia, Moscow, Russia.

Phylogenetic Justification. This fossil preserves the all the synapomorphies of the subfamily Gomphaeschninae : lack of crossveins in the antesubnodal area between RA and RP, no accessory cubitoanal crossveins in the submedian space between CuP- crossing and PsA and the discoidal triangle only divided into two cells by a single crossvein ( Bechly et al., 2001).

Minimum Age. 139.8 Ma.

Age Justification. Found in Zara Formation, Zazinsk series at Baissa near the uppermost course of Vitim River, Transbaikals, Eravninsk region, Buryat Republic ( Tyumen), Russia. The Zara Formation is Berriasian (145.0–139.8 Ma; Lower Cretaceous) in age, according to ( Cohen et al., 2013). Thus the minimum age of the Berriasian is used for the calibration.

Discussion. This fossil has not yet been used in a molecular divergence estimation. Although the specimen has this been tested phylogenetically for its inclusion within the genus Gomphaeschna , evidence from synapomorphies supports its use as a calibration for crown Aeshnidae . The oldest fossil record of the basal aeshnid subfamily Gomphaeschninae was chosen to calibrate this node. Baissaeschna prisca Pritykina, 1977 , belonging to the Allopetaliinae ( Bechly et al., 2001), has been found in the same strata of the Zara formation and hence provides additional support for the calibration of this node. Gomphaeschna? sibirica , was described by Bechly et al. (2001) from a Siberian locality of similar Lower Cretaceous age.