Meganeuropsis is an extinct genus of griffinfly, order Meganisoptera, known from the Early Permian Wellington Formation of North America, and represents the largest known insect of all time. Meganeuropsis existed during the Artinskian age of the Permian period, 290.1–283.5 mya. The genus includes two described species by Frank Morton Carpenter, fossil insect curator at the Museum of Comparative Zoology at Harvard University: 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 330 mm, an estimated wingspan of up to 710 mm, and a body length from head to tail of almost 430 mm. The holotype is held in the Museum of Comparative Zoology. Meganeuropsis americana, discovered in Noble, Oklahoma in 1940, is most probably a junior synonym of Meganeuropsis permiana. It is represented by a forewing fragment 280 mm long. The complete reconstructed wing had an estimated total length of 305 mm, making it the largest insect wing ever found (with a resulting wing span of 690 mm). The holotype is held in the Museum of Comparative Zoology.