
Oxygen wasn’t the bottleneck for giant Paleozoic insects, new study finds
A new study across 44 insect species shows that the tracheal system in insects wouldn’t need dramatic expansion as size increases, meaning the ancient giants like Meganeuropsis permiana could still deliver oxygen efficiently. The finding undermines the long-held oxygen-constrain hypothesis and suggests giant bugs weren’t blocked by atmospheric oxygen after all; other factors—predation by aerial vertebrates, heat buildup during flight, molting/structural constraints, and open circulation—likely helped limit insect size, with future research exploring the role of air sacs in ventilation.













