Named By: Charles Brongniart - 1885.
Classification: Arthtropoda, Insecta, Odonatoptera, Protudonata, Meganeuridae.
Species: M. brongniarti, M. monyi, M. vischerae.
Size: Over 75 centimeter wingspan.
Known locations: Western Europe. Specifically Commentry in France and Bolsover in Derbyshire, England.
Time period: End of Carboniferous.
Fossil representation: Well preserved specimens.
discovered in France in 1880, Meganeura is one
of the largest known
flying insects to ever exist. Although superficially similar to a
dragonfly, Meganeura and others like it are
generally referred to as
griffinflies, due to morphological differences between them and the
It is generally considered that the maximum potential size of an insect is dictated by how much oxygen is available for respiration. The oxygen content of our atmosphere today is typically 21% of the total gases, but back in the Carboniferous it was much higher at up to 35%. Insects like Meganeura breathe through a system of tracheal tubes that carry oxygen directly into their internal tissues. A higher amount of oxygen in the atmosphere would supply a passive boost to these tissues with no effort on the part of Meganeura allowing for the larger growth. Falling oxygen levels after this period would mean that the giant insects simply did not have enough oxygen to maintain their size, resulting in either the evolution of smaller forms, or outright extinction of the larger.
Meganeura is likely to have hunted and fed in much the same way as dragonflies do today, although its larger size may suggest that many more creatures could have been on the menu for it. Aside from other invertebrates potential prey may have also included small amphibians that were rapidly evolving to terrestrial life.