Huge flying reptile sets Jurassic record
CBC
A fossil jawbone peeking out from a limestone seashore on Scotland's Isle of Skye led scientists to discover the skeleton of a pterosaur that showed that these remarkable flying reptiles got big tens of millions of years earlier than previously known.
Researchers said on Tuesday this pterosaur, named Dearc sgiathanach, lived roughly 170 million years ago during the Jurassic Period, soaring over lagoons in a subtropical landscape and catching fish and squid with crisscrossing teeth perfect for snaring slippery prey.
Its scientific name, pronounced "jark ski-an-ach," means "winged reptile" in Gaelic.
With a wingspan of about 2.5 metres (eight feet), Dearc was the Jurassic's largest-known pterosaur and the biggest flying creature that had inhabited Earth to that point in time. Some pterosaurs during the subsequent Cretaceous Period achieved much greater dimensions — as big as fighter jets. But Dearc shows that this scaling up had its origins much earlier.
A forensic analysis of its bones indicated this Dearc individual was not fully grown and could have had a three-metre (10-foot) wingspan as an adult.
Dearc weighed very little — probably below 10 kilograms (22 pounds) — thanks to its hollow, lightweight bones and slender structure, said University of Edinburgh paleontology doctoral student Natalia Jagielska, lead author of the research published in the journal Current Biology.
It had an elongated skull and a long, stiff tail. An arsenal of sharp teeth formed a cage when it bit down on prey.
Pterosaurs, which lived alongside the dinosaurs, were the first of three vertebrate groups to achieve powered flight, appearing about 230 million years ago. Birds appeared about 150 million years ago and bats around 50 million years ago.
Pterosaurs are some of the rarest vertebrates in the fossil record, owing to their fragile bones, some with walls thinner than a sheet of paper.
"Our specimen, anomalously, is well preserved — retaining its original three dimensions and being almost complete, and still articulated as it would be when alive. Such state of preservation is exceptionally rare in pterosaurs," Jagielska said.
Up until when Dearc lived, pterosaurs generally had been modest in size, many about the size of a seagull.
The prevailing wisdom among scientists had been that pterosaurs did not reach Dearc's size until the Cretaceous, some 25 million years later, with the appearance of creatures like Huanhepterus, Feilongus and Elanodactylus.
Quetzalcoatlus, appearing about 68 million years ago, boasted a wingspan of about 11 metres (36 feet), like an F-16 fighter.
"In the Cretaceous, some pterosaurs got enormous. These were some of the most superlative animals that ever lived. Dearc was not close to them in size or grandeur, but it was 100 million years older. Evolution needed time to make such giants," said University of Edinburgh paleontologist and study co-author Steve Brusatte.
