Oxygen myth busted: giant ancient griffinflies may not have been oxygen-limited
A new Nature study suggests that the long-held view that atmospheric oxygen alone drove the enormous size of prehistoric flying insects like griffinflies isn’t supported by their data; researchers found tracheoles occupy only about 1% of flight muscle across sizes, implying oxygen delivery wasn’t the hard limit on size. The findings shift the question to other factors—ecology, predators, and biomechanics of an external skeleton—though the exact reason giant insects existed and disappeared remains unclear.
