This fossil insect wing (Stephanotypus schneideri) from the period about 300 million years ago when insects reached their greatest sizes, measures 19.5 centimeters (almost eight inches) long. The largest species of that time were even bigger, with wings 30 centimeters long. For comparison, the inset shows the wing of the largest dragonfly of the past 65 million years. Credit: Wolfgang Zessin