Giant prehistoric insects didn’t need high oxygen after all, study finds

Ancient Earth once buzzed with enormous dragonfly-like insects, and scientists long thought high oxygen levels made their size possible. A new study overturns that idea, revealing insect flight muscles weren’t constrained by oxygen after all. Their breathing system has plenty of room to expand, meaning oxygen alone can’t explain their giant forms. Now, researchers are searching for new answers—like predators or physical limits of their bodies.