Meganeura (gr. "Great nerves (or veins)", referring to the network of veins or ribs of its wings) is an extinct genus of protodonate insects of the family Meganeuridae. Among its species is Meganeura monyi, an insect related to today's dragonflies, which lived in the Carboniferous period (300 Ma). With a wing span of more than 70 cm, it is the largest known species of insects to ever exist on Earth. The Permian species Meganeuropsis permiana is also large. They were predatory insects that fed on other insects and even small amphibians.
Its fossils were discovered in the Estefanian age strata of Commentry, in France, in 1880; In 1885, the French paleontologist Charles Brongniart described the fossil and gave it its name. Another good fossil specimen was found in Bolsaver, Derbyshire, in 1979. The holotype is housed in the Museum of Natural History in Paris.
M. americana, discovered in Oklahoma in 1940, is a species represented by the largest insect wing ever found; is preserved in the Harvard Museum of Natural History.
The size of carboniferous insects[]
There is some controversy about how the insects of the Carboniferous period could reach such enormous proportions. The way oxygen diffuses through the insect's body through its tracheal respiratory system sets an upper limit on body size, which prehistoric insects seem to have surpassed. It was originally proposed (Harlé and Harlé, 1911) that Meganeura was capable of flight since the atmosphere at that time contained a proportion of oxygen greater than the current 21%. This hypothesis was discarded by other scientists, but has found approval more recently after subsequent studies on the relationship between gigantism and oxygen availability. If this theory is correct, these giant insects would have been vulnerable to declining levels of oxygen. oxygen and certainly couldn't survive in today's atmosphere.
However, more recent research indicates that insects do indeed breathe, with "rapid cycles of tracheal compression and expansion." If this is true, then there is no need to postulate the presence of an atmosphere with a high partial pressure of oxygen.
Another explanation is the absence of predators. It is known that the birds increased in variety and quantity coinciding with the reduction in size of the large flying insects.
Popular culture[]
- Meganeura appears briefly in the BBC series Walking with Monsters, where he snatches a small reptile from a giant spider.
- Meganeura also appears in the ITV series Prehistoric Park, where he lives in a large glass dome alongside an Arthropleura and a Pulmonoscorpius.
Other uses[]
- Meganeura is a scientific journal on fossil insects.
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