Giant dragonflies once roamed Earth’s skies. New research upends the textbook theory of why they went extinct

The extinct griffinfly had a wingspan of up to 70cm. Werner Kraus / Wikimedia, CC BY

Insects first took to the skies about 350 million years ago, some 200 million years before birds first flapped their wings.

By the end of the Carboniferous period, 300 million years ago, some flying insects had become gigantic. Huge dragonfly-like insects called griffinflies had wingspans of 70cm – five times the size of the largest modern dragonflies.