ODONATA

CROWN ODONATA View in CoL

Node Calibrated: (1) Crown Odonata . This node represents the order crown Odonata (Zygoptera + Anisozygoptera + Anisoptera ).

Species. Triassolestodes asiaticus ( Triassolestidae ) Pritykina, 1981

Specimen. PIN 2240 View Materials /1783 at Paleontological Institute of the Academy of Science of Russia, Moscow, Russia. This fossil is a hind wing representing the holotype of Triassolestodes asiaticus .

Phylogenetic Justification. Triassolestodes was attributed by Nel et al. (1993) to the paraphyletic grade "Anisozygoptera", but subsequently shown to belong to Triassolestidae (Epiprocta: Isophlebioptera) by Bechly (1997) and Nel et al. (2002). The latter authors redescribed the holotype, listed synapomorphies (like AA and CuP and MP and CuA are partly fused basal of the arculus in the hind wing) in support of the attribution, and also provided a parsimony-based analysis, which confirmed Triassolestodes fell within the Isophlebioptera-Triassolestidae clade.

Minimum Age. 237 Ma.

Age Justification. The type location of this fossil is Dzhayloucho, near Madygen, south of Fergana Valley, Kyrgyzstan. Found in Upper Triassic, Ladinian-Carnian of the Madygen Formation. The attribution of this fossil to Ladinian (242–237 Ma) rather than Carnian (237–227 Ma) by Shcherbakov (2008) is based on the megaflora ( Shcherbakov, 2008), which is significantly different and more primitive than that of other Carnian localities (e.g., Ipswich Insect Beds in Australia or Molteno Formation in South Africa).

PALAEO- ELECTRONICA.ORG

Discussion. This fossil has not yet been used in molecular divergence time analyses, but will be useful in studies exploring divergence between Ephemeroptera and Odonata . Several other fossil Triassolestidae have been described from the same age: Mesophlebia antinodalis Tillyard, 1916 and Triassolestes epiophlebioides Tillyard, 1918 (227 Ma, Carnian, Ipswich, Australia), Triassoneura andersoni Riek, 1976 (Carnian, Molteno Formation, South Africa), and Triassothemis mendozensis Carpenter, 1960 (Carnian, Argentina). Two slightly younger but still undescribed fossil Isophlebioptera-Isophlebioidea have been found in the Carnian (232 Ma) of Bavaria, and the Carnian (230 Ma) of Steigerwald in Germany ( Bechly, 2015). All these fossil Isophlebioptera also provide a minimum age for the stem group clade Epiprocta (and thus indirectly for stem group Zygoptera), because Isophlebioptera is more closely related to Epiophlebiidae + Anisoptera than to Zygoptera.