Advanced Search

The story appears on

Page A6

May 7, 2019

GET this page in PDF

Free for subscribers

View shopping cart

Related News

Home 禄 Nation

Study sheds light on avian flight

Source: Xinhua | 08:34 UTC+8 May 7, 2019 | Print Edition

A CHINESE study found that running may have caused early winged dinosaurs to flap their wings before they evolved the ability to fly, providing new insights into the origin of avian flight.

Since a nearly complete Archaeopteryx fossil specimen was discovered in 1861, there has been a debate on 鈥済liding or flapping鈥 when researchers discuss how these primitive birds once flew.

Some researchers suggested that the Archaeopteryx, which lived about 150 million years ago, probably glided between trees as shafts in their feathers could not stand up to flapping. Some researchers hold a different opinion, suggesting the wings of the Archaeopteryx could withstand active flapping.

In the new study, researchers from Tsinghua University and the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, chose the Caudipteryx as the candidate to explore how running may have played a part in the evolution of flight.

Living about 125 million years ago, the peacock-sized Caudipteryx, like the Archaeopteryx, belongs to a group of dinosaurs called maniraptoran, which includes birds and some non-flying dinosaurs.

In the American journal of PLOS Computational Biology, researchers reported that they first used a mathematical approach to analyze the mechanical effects of running on various parts of a Caudipteryx 鈥 body, two legs, two wings, tail, neck and head.

Calculations revealed that with an estimated maximum running speed of 8 meters per second, running speed of between about 2.5 and 5.8 meters per second would have created forced vibrations that caused the dinosaur鈥檚 wings to flap. To test the calculations, researchers built a life-size robot of the Caudipteryx that could run at different speeds, confirming that running caused a flapping motion of the wings.

They also verified the results on young ostriches that weigh 4.7 kilograms, similar to a middling Caudipteryx. They fixed the ostriches with artificial wings which were equipped with sensors to measure the lift, thrust or drag forces produced by the wings while running.

A total of four sets of wings in different sizes were tested. The results showed that running indeed caused the wings to flap, and longer and larger wings provided a greater lift force.

Nation
锘

 

Copyright 漏 1999- Shanghai Daily. All rights reserved.Preferably viewed with Internet Explorer 8 or newer browsers.

娌叕缃戝畨澶 31010602000204鍙

Email this to your friend


锘