Dinosaurs grew wings not to fly but to create a flap, say scientists

DINOSAURS first grew wings to scare their prey and make them easier to catch, a study suggests.

Early dinosaur wings evolved as a means to frighten animals while hunting, and only later became used for flying, scientists say. Theories on the evolution of wings have been discussed for years and engineers and scientists at the Seoul National University built a small robot dinosaur called Robopteryx to try to understand their origins.

The machine, which resembled a golf trolley covered with black feathers, was wheeled up to grasshoppers and the scientists moved the wings, imitating “flush-pursuit” hunting methods, to see if it would cause the insect to flee.

The grasshopper moved in fear 93 per cent of the time when confronted by wings and feathers, twice as often as without. The study, published in Scientific claims that the small wings were initially too weak to fly and evolved as a hunting tool before later becoming tools for flight.

“We believe that pennaceous feathers evolved first and were used later for flight,” study first author Jinseok Park told The Telegraph. “During the pursuit process, feathers might have aided in manoeuvring, jumping, leaping, and pouncing.” He said the study offers a “convincing explanation” for early dinosaur wings and feathers.

The larger surface area with feathers, he says, was better at scaring prey, and fast-flapping was also useful.

These ideas, he said, suggests that wings were only used for flight as a side-effect, an evolution that came to some ground-based dinosaurs. The study also built a robot to mimic the Caudipteryx, a common and small ground-based raptor that lived around 124 million years ago. Grasshopper response was used in the study because their ancestors lived alongside dinosaurs millions of years ago.

Robopteryx was equipped with nine motors and was programmed to imitate the movements of forelimbs and tail of ground-foraging flush-pursuing birds, such as the greater roadrunner and the rufous-tailed scrub robin, both thought to be descended from dinosaurs.

“We propose that using plumage to flush prey could increase the frequency of chases after escaping prey, thus amplifying the importance of proto-wings and tails in manoeuvring for successful pursuit,” said co-author Sang-im Lee from DGIST.

“This could lead to the development of larger and stiffer feathers as these would enable more successful pursuits and pronounced visual flush-displays.”

‘During the pursuit, feathers might have aided manoeuvring, jumping, leaping and pouncing’