Evolution of flight: The Size and Energetic Constraints on Giant Dragonfly Flight

Giant dragonflies (griffenflies) were the largest insects in natural history and were precursors to modern dragonflies and other insects. The largest fossils show an impressive wing lenth of 30 cm. This gigantism is correlated with the increased oxygen levels during the Permian period (300-270 million years ago). The upper limit on size depends on body form, oxygen levels, metabolic rates, and muscle energetics. I use physical arguments to predict the size range, wing motion, and flight energetics of these insects. The predicted size range encompasses the fossil records found in the US, France, and Russia. I will further present computational results on flight energetics. These physical arguments also predict the size range of other flying insects due to oxygen fluctuations during their evolutionary history.