FOUR WINGS GOOD, TWO WINGS BETTER

摘要

Almost a decade ago, fossil-hunters in China unearthed something remarkable: a feathered dinosaur with four wings. Microraptor was no one-off: other four-winged fossils have come to light since. How did these beasts get around, and why did four wings lose out to two? The key to understanding four-winged flight is to realise that flying is about more than getting off the ground. "If you are flying in a forest it behoves you not to hit the trees," says Michael Habib at the University of Southern California in Los Angeles.