In 2002, the fossil of a four- winged dinosaur was discovered in china and named a microraptor. what was the significance of the discovery

The answer is: the discovery resulted in some theories about the origin of flight.

Microraptor was a four-winged dinosaur, that lived about 120 million years ago. It is suggested that it was able to fly using all for limbs. It also had feathers, which suppose the connection between birds and dinosaurs. But, its feathers are used for gliding and not for flying. This suggests that flight evolved in the trees and not on the land.