The bizarre, bird-like dinosaur Microraptor gui appears to have four wings: both its front and back limbs were feathered. And those rear leg feathers weren’t just decorative; they show adaptations for flight. But could this creature really fly? Probably not far under its own power. But it might have glided down from trees, perhaps even flapping its front limbs.
Microraptor gui was the first dinosaur ever found with asymmetrical feathers on its back legs. Why is that a big deal? Early feathers may have evolved for many reasons, such as temperature regulation or courtship rituals. Asymmetrical feathers, though, are adapted specifically for moving through the air, suggesting this dinosaur used those feathered back legs to flap or glide.
To learn how Microraptor gui might have used its two sets of feathered limbs, scientists tested models in wind tunnels. The results suggested Microraptor may have adopted a position with its back legs splayed apart to form a second airfoil, like an early biplane. Some birds, in fact, may have followed an evolutionary path similar to what we see in airplane design: as the primary wings improved over time, a second set became unnecessary.
See a fossil cast and life-sized model of Microraptor gui, along many other dinosaurs and early birds, at Dinosaurs Among Us, now on view.