Scientific American has a piece on the origins of pterosaurs. A group of animals called lagerpetids are now thought to e the ancestors of pterosaurs. These animals lived between 237 and 201 million years ago during the Triassic Period. The details are in a paper in the journal Nature, which was published by Sterling Nesbitt, Martin Ezcurra, and others.
For more than 160 million years, pterosaurs soared over the earth. They were as much a part of the Age of Reptiles as dinosaurs were, and they were the first vertebrates to fly by flapping. But how did these leathery-winged creatures evolve to take to the air in the first place? Paleontologists have puzzled over this question for more than a century. Thanks to new fossil evidence from locales as far apart as New Mexico and Argentina, the forerunners of pterosaurs are finally coming into view.
Until now, precisely what these predecessors looked like was anyone’s guess. “Pterosaurs appear in the fossil record as pterosaurs,” with no consensus on what reptiles they evolved from, says Virginia Tech paleontologist Sterling Nesbitt. Part of the problem is that pterosaurs and their forerunners were very delicate. “Pterosaurs are extremely fragile,” says paleontologist Natalia Jagielska of the University of Edinburgh in Scotland, who was not involved in the new research. And skeletal adaptations that were important for flight—such as ultralight hollow bones—also made pterosaurs and their precursors especially vulnerable to the forces involved in fossilization, which can destroy parts of the skeleton and flatten preserved bones. Only very particular, and relatively gentle, environmental circumstances allowed pterosaurs to become fossilized clearly enough to study.
A new analysis, published by Nesbitt, Martín Ezcurra and their colleagues on Wednesday in Nature, proposes that a group of lanky, slender reptiles called lagerpetids were close relatives of pterosaurs. The fossils of these strange, wingless animals already show traits shared with the flying reptiles, offering what the researchers call a rough image of what pterosaur predecessors were like.
