Reconstruction of Caudipteryx robot to identify the origin of avian flapping flight

The origin of bird and avian flight is one of the most controversial debates since the fossil of Archaeopteryx was found in Germany. With the continuous discoveries of relative fossils of dinosaurs from all over the world, scientists have reached a consensus that the ancestors of bird might be small sized non-avian theropod dinosaurs. However, the disputation focus now remains in how the dinosaur learned to fly. Via analysis of kinematics and dynamics of reconstructed Caudipteryx robot on the test rig, we discovered that the flapping motion of the forearms of feathered dinosaurs was developed as they were only able to run on the ground when it was long before it could actually fly in the sky. This study supports the inferences that the performance of powered flapping flight was evolved long before the feathered dinosaurs could fly. This is a completely natural biophysical principle that provides a vital role to comprehend the evolution of avian flight.