Dragonflies are the sharks of the insect world—streamlined, quick, and ruthless. But the thousands of dragonfly species zooming around today are small potatoes compared to their ancient ancestor Meganeura. With wingspans reaching up to 25 inches, these monsters were among the largest insects ever to buzz around the Earth, and were the scourge of the skies 300 million years ago. The Carboniferous period was a weird time to be alive, and we're glad we've left the giant, predatory insect far behind us.
Image by omg-stock.