Meganeuropsis is an extinct genus of griffinfly, order Meganisoptera, known from the Early Permian (299-272 million years ago) of North America, and represents the biggest known insect of all time.
The genus includes two described species:
Meganeuropsis permiana described in 1937 from Elmo, Kansas. It was one of the largest known insects that ever lived, with a reconstructed wing length of 330 millimetres (13 in), an estimated wingspan of up to 710 millimetres (28 in), and a body length from head to tail of almost 43 centimeters (17 in).
Meganeuropsis americana, discovered in Oklahoma in 1940, is most probably a junior synonym of Meganeuropsis permiana. It is represented by a forewing fragment 28 centimeters (11 in) long, which is conserved and displayed in the Harvard Museum of Natural History; the complete reconstructed wing had an estimated total length of 30.5 centimeters (12.0 in), making it the largest insect wing ever found (with a resulting wing span of 69 centimeters /27 in). Photo: leandrosanchesarte.blogspot.com