Fossil of Scottish bird reptile leaves scientists “disappointed” – 02/24/2022 – Science

A fossil of the lower jaw that rose to the surface in a limestone area off the coast of the Isle of Skye, Scotland, prompted scientists to discover the skeleton of a pterosaur, proving that this remarkable flying reptile grew tens of millions of years ago. . than previously thought.

On Tuesday (22) researchers announced that the aforementioned pterodactyl dear c sjitanaklived about 170 million years ago during the Jurassic period, flying over shallow lakes in a subtropical region and hunting fish and squid with its serrated teeth, perfect for catching slippery prey.

The scientific name, pronounced “djárk ski-an-ach” means “pterodactyl reptile” in Gaelic.

With a wingspan of about 2.5 meters, it is the largest known flying creature from the Jurassic period, and the largest flying creature that existed on the planet until that time. Some pterosaurs reached larger dimensions in the later Cretaceous period, when they reached the size of hunting jets. But Dirk shows that this major advance arose much earlier than he had imagined.

Forensic analysis of his bones indicates that this particular specimen of Dirk was still growing and could reach a wingspan of ten feet.

Dirk was very small – perhaps less than 10kg – thanks to his light, hollow bones and slim frame, said Natalia Jagelska, a PhD student in paleontology at the University of Edinburgh and lead author of the report published in the current scientific journal. biology.

The animal had an elongated skull and a long, solid tail. An arsenal of sharp teeth formed a cage when it approached the prey.

Pterosaurs, which lived with dinosaurs, were the first of three groups of vertebrates to achieve the ability to pay for flight, 230 million years ago. Birds appeared about 150 million years ago, and bats appeared about 50 million years ago.

Pterosaurs are among the rarest vertebrates in the fossil record, due to the fragility of their bones, which in some cases had walls thinner than a sheet.

“Our specimen is an anomaly in that it is so well preserved—it retains its original three dimensions and is nearly complete, still articulated as it would have been alive. This state of preservation is exceptionally rare in pterosaurs,” Jagelska said.

Until the time when Dirk lived, pterosaurs were generally of modest size, and many of them never exceeded the size of a gull. The prevailing view among scientists was that pterosaurs did not reach the size of Dirk until the Cretaceous period, about 25 million years later, with the emergence of creatures such as Huanhepterus, Feilongus, and Elanodactylus. Quetzalcoatlus, which appeared about 68 million years ago, had a wingspan of about 11 meters, similar to an F-16 fighter plane.

“In the Cretaceous, some pterosaurs became huge. They were some of the most superior animals ever. Dirk didn’t even come close to them in size or grandeur, but they appeared 100 million years ago. Evolution took time to produce giants.” Like these, he said. Steve Brusatte, a paleontologist at the University of Edinburgh and co-author of the study.

“One idea is that pterosaurs didn’t grow until after birds evolved, when the two groups were competing for air vents. But Dirk tells us that pterosaurs reached the size of today’s largest birds even before the first birds. Which disproves this hypothesis.”

In Dirk’s time, the United Kingdom was closer to the equator, and existed as a chain of separate islands. Dirk lived with a number of carnivorous dinosaurs, herbivores, mammals, and marine reptiles.

Dirk was discovered in 2017. The fossil arose from a limestone area at the tidal range, and was visible at low tide.

“We were surprised,” Brusatte said. “Nothing like this has been found in Scotland yet.”
They fought the tide, using first hammers and chisels and later diamond-tipped saws. But the tide stopped the work before the fossil was excavated.

“The tide came in strong and we cried when we saw waves covering the hole. We thought we had lost it,” Brusatte said. “But we decided to go back to the place at midnight with lamps and lanterns. We were shocked but happy to find that the bones were still there when the waves receded.”

Translated by Paolo Migliacci.