Giant Bugs Eaten Out of Existence by First Birds?
Without avian predators, bugs today would be much bigger, study says.
Today insects are among the smallest creatures on Earth, but about 300 million years ago, huge bugs were fairly common. The dragonfly-like griffinfly, for example, had a wingspan of about 28 inches (70 centimeters)—"a little bit smaller than a crow's," study co-author Matthew Clapham said. Today's widest-winged insects are butterfly and moth species that span about a foot (30 centimeters).
The prehistoric bugs' incredible growth was fueled by an atmosphere that was more than 30 percent oxygen, compared with 21 percent today, experts say. The extra oxygen gave bugs more energy per breath, allowing them to power bigger bodies.
(Related: "Did Rising Oxygen Levels Fuel Mammal Evolution?")
In the new study, Clapham and a colleague created a wingspan database for more
