AESHNIDAE, Rambur, 1842

Kohli, Manpreet Kaur, Ware, Jessica L. & Bechly, Günter, 2015, How to date a dragonfly: Fossil calibrations for odonates, Palaeontologia Electronica 19, pp. 1-14 : 6-7

CROWN AESHNIDAE

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.