Just as babies learn to crawl before they can walk, the first birds had to run before they could fly. This is what a group of engineers at Tsinghua University in China say.
This theory goes against the ideas of most paleontologists about the beginning of flight.
Scientists distinguish between two types of flight, gliding, for example, from one tree to another, and active flight, where birds take off with their own wing power.
The generally accepted theory is that gliding came first and birds with gliding abilities gradually developed active flight.
Doubts about the theory
The Chinese engineers have studied another idea. They have carefully examined the fossils of a 5 kg lizard, Caudipteryx that lived 125 million years ago.
She walked on strong hind legs, but her forelimbs looked like wings, although they were much too small for flight. Nevertheless, the engineers wanted to find out if the wings moved when the lizard ran and calculated how vibrations from the body were transmitted to the wings during running.
The results showed that when Caudipteryx reached a speed of 2.5 m per second, the wings began to swing up and down.
The engineers then built a robot robot with the same configuration and let the device run on a treadmill, and the exact same thing happened there.
Therefore, they believe that pre-needles may have learned active flight without starting to glide. The two methods could therefore have developed in parallel but independently of each other.
