Pterosaurs were egg layers
2004-06-10 10:46
Paris - The world's first discovery of a fossilised embryonic pterosaur has confirmed suspicions that these strange flying cousins of the dinosaurs were egg layers, a study published on Thursday in the British weekly journal Nature said.
The embryo, 121 million years old, was found snuggled inside fragments of eggshell, its leathery wing membranes and skin imprints "exquisitely preserved", Chinese fossil hunters said.
The creature "was probably enjoying its last few days in the egg before hatching out to walk on the Early Cretaceous earth" before it was smothered, possibly by a volcanic eruption, they added.
The find is remarkable because good pterosaur fossils are very rare.
Pterosaur bones were light and very fragile, and their fossilised remains tend to be crushed or mashed. Indeed, until now, no one had ever found an embryo of this species.
The specimen was unearthed in shale in Jingangshan in western Liaoning, northeastern China, a location that has yielded almost uncountable dinosaur treasures.
Its folded wings, tucked inside the egg, give it a wingspan of 27cm.
Had it lived, it would have grown into a medium-to-large pterosaur, a category that would give it a wingspan of between three and six metres.
Pterosaurs, a classification that includes pterodactyls, have been tracked to deposits from the Upper Triassic, 200 million years ago. They survived until the twilight of the dinosaurs at the end of the Late Cretaceous period, some 65 million years ago.
Authors of the study are Wang Xiaolin and Zhou Zhonghe of the Institute of Vertebrate Palaeontology and Palaeoanthropology at the Chinese Academy of Sciences.