Dragonflies Ruled the Sky Before Dinosaurs With 2-Foot Wings

Before dinosaurs existed, dragonflies with 2-foot wings ruled the sky.

300 million years ago in the Carboniferous period, a dragonfly called Meganeura monyi had a wingspan of 65 to 75 centimetres - the size of a pigeon, or a modern eagle's wing. It hunted in forests of 100-foot-tall ferns and club mosses.

They could get that big because the atmosphere was 35% oxygen, compared to 21% today. More oxygen meant insects could grow larger through their tracheal breathing system. No birds existed yet. No pterosaurs. The sky belonged entirely to insects.

Fossils from France and England show they had massive mandibles and spiny legs for grabbing prey mid-air. They were apex predators 100 million years before the first dinosaur. When oxygen levels fell and birds evolved, they shrank to the size we know today. The age of giants was over, but their descendants still patrol your garden.