NEW YORK - Insects with wingspans of more than two feet ruled the skies until 150 million years ago, when predatory birds evolved into skilled flying bug-zappers, according to a study.
The insects originally grew in tandem with rising oxygen levels until birds developed, the research found. The study, published in the Proceedings of the National Academy of Sciences, suggests the bugs then got smaller as a way to maneuver away from the avian predators.
