The oldest aktassiid dragonfly (Odonata: Petaluroidea) from the Middle Jurassic of China

Abstract

A new genus and species of true dragonfly Hongtaous caii gen. et sp. nov. is described from the Middle Jurassic of Inner Mongolia, China. It is assigned to the family Aktasiidae based on the following: large and broad wings; narrow postnodal area with many cells distal of elongated pterostigma; very long and straight IR1; and widened area between RP1 and RP2, which is the oldest member of this family to date. Hongtaous caii sp. nov. differs from other genera by the configuration of wing venation such as: two rows of cells between RA and RP1 at level of Pt, and extending to the end of the wing; an elongated IR1, not distally vanishing; discoidal triangle and subdiscoidal triangle divided into multiple cells by transverse veins; presence of Rspl. In addition, its special cerci are simply discussed.