Scientists discover how this prehistoric reptile could fly

By Chris Dyer via SWNS

A species of flying reptile related to dinosaurs were able to evolve and take to the skies using aerodynamic features in their wings similar to modern planes, scientists discovered.

Pterosaurs - known as pterodactyls - are the closest relatives of dinosaurs and roamed the Earth for over 160 million years, from around 200 million years ago during most of the Mesozoic until the end of the Cretaceous period.

The flying reptiles that feasted on insects and small animals were the first vertebrates to evolve powered flight.

Their wings were formed by a membrane of skin, muscle and other tissues stretching from the ankles to a dramatically lengthened fourth finger.

But many details of how pterosaurs were able to fly as well as their anatomy and performance that made it possible are still unclear, scientists said.

Now new research revealed that pterosaurs evolved a muscular wing-body shape to reduce drag and improve its flight performance.

Scientists found the reptile developed a wing that allowed better streamlining to help it to glide through the air.

Experts from the University of Hong Kong (HKU) used laser-stimulated fluorescence to photograph the bones and reveal soft tissues of a Late Jurassic pterodactyloid pterosaur fossil to analyze how it flew.

This involved scanning the fossil with a violet laser and taking long-exposure photographs of the fluorescence produced by the pterosaur’s bones and revealed soft tissues.

The results suggested the pterosaur had a wing root fairing to increase streamlining - a feature that smooths the airflow around the wing-body and reduces drag, as in the wing root fairings of most modern airplanes and flying animals.

Unlike bats and birds, the pterosaur wing root was unique in being primarily made of muscle rather than fur or feathers.

Dr. Pittman, research assistant professor of the Department of Earth Sciences and Vertebrate Palaeontology Laboratory at HKU, said: “This muscular wing root fairing appears to have provided pterosaurs with additional flight benefits, such as improved force generation during the flight stroke and sophisticated control of the wing's shape, including minimizing unwanted vibrations or ‘flutter’.”

As a muscular feature, pterosaurs appeared to have used their aerodynamic wings to improve their flight performance through sophisticated control of their wing root and help lift and move the wings during the flight stroke.

Pterosaurs operated uniquely with a membrane wing held in tension by a hyper-elongated fourth finger, researchers said.

Bats are the only surviving vertebrate-powered flyers that use a membranous wing, but this is supported by a hyper-elongated hand, while birds use a feathered wing to fly.

As powered, flapping flyers, pterosaurs, bats, and birds all used lift to provide both weight support and thrust, scientists said.

Powered flight in all animals comes at the cost of essentially “pushing” against drag - or more precisely, injecting enough momentum to the air to overcome drag, the experts added.

Luke Barlow, a research assistant in Dr. Pittman’s lab that studied the specimen, said: “In birds, the wing root fairing is made of feathers. In bats, the wing root fairing is made of fur. In contrast, pterosaurs had a wing root fairing primarily made of skeletal muscle.”

For manufactured aircraft, engineers work to minimize drag effects by creating streamlined aerodynamic outlines of the craft, including adding aerodynamic 'fairings' to smooth shapes and joints on the aircraft, including the wing root, wingtips, and the landing gear.

Fairings are typically curved sections and are used to direct airflow smoothly over the structure, which reduces profile drag and, in some cases, help prevent stall by delaying flow separation.

Wing root fairings are commonly added between the aircraft fuselage and the wing, especially in low wing configurations where a fairing shows greater benefit, but not all shapes change airflow in a desirable way, scientists said.

However, fairings are not always added to planes due to economic reasons.

Thomas Kaye, a co-author of the study and director of the Foundation of Scientific Advancement in the United States, said: “Our work shows that pterosaurs were more advanced flyers than we thought, even in the Late Jurassic when birds had just evolved flight.

“Our study also highlights the potential contributions of new technologies to our understanding of pterosaur flight anatomy and evolution. We are excited to see where our work takes us next.”

The findings of the study were published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).