Meganeuropsis
Meganeuropsis is an extinct genus of griffinfly, order Meganisoptera, known from the Early Permian Wellington Formation of North America, and represents the biggest known insect of all time. Meganeuropsis existed during the Artinskian age of the Permian period, 283.5–290.1 mya. The genus includes two described species:
Meganeuropsis permiana described in 1939 from Elmo, Kansas. It was one of the largest known insects that ever lived, with a reconstructed wing length of, an estimated wingspan of up to, and a body length from head to tail of almost.
Meganeuropsis americana, discovered in Oklahoma in 1940, is most probably a junior synonym of Meganeuropsis permiana. It is represented by a forewing fragment long, which is conserved and displayed in the Harvard Museum of Natural History; the complete reconstructed wing had an estimated total length of, making it the largest insect wing ever found.