Meganeuropsis is an extinct genus of griffinfly, order Meganisoptera, known from the Early Permian 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 the largest known insect 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 430 millimetres (17 in).[1]
Meganeuropsis americana, discovered in Oklahoma in 1940, is most probably a junior synonym of Meganeuropsis permiana.[2][3] It is represented by a forewing fragment 280 millimetres (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 305 millimetres (12.0 in), making it the largest insect wing ever found (with a resulting wing span of 690 millimetres (27 in)).