That's so cool! At 63cm, I wouldn't exactly call it a dragon fly though...A flying squirrel maybe? :D
Meganeura is a genus of extinct insects from the Carboniferous period approximately 300 million years ago, which resembled and are related to the present-day dragonflies. With wingspans of up to 65 cm (25.6 in), M. monyi is one of the largest known flying insect species; the Permian Meganeuropsis permiana is another. Meganeura were predatory, and fed on other insects, and even small amphibians.
There was a study where by increasing the amount of oxygen in the air, in just a few generations, insect were gaining as much as 10% in size.