Scientists explain the origin of pterosaurs, flying reptiles from the dinosaur era

Scientists may have solved one of the most enduring paleontological mysteries – the evolutionary origins of flying reptiles called pterosaurs that ruled the sky, while dinosaurs dominated the land.

Researchers said Wednesday that a Triassic group of reptiles called lagerpetids, known from partial skeletons from the United States, Argentina, Brazil and Madagascar, appeared to be a precursor to pterosaur evolution.

Lagerpetids, which first appeared about 237 million years ago, are generally small in size and are probably bipedal insectivores. They can’t fly. Pterosaurs became Earth’s first flying vertebrates, with birds and bats appearing much later.

“The origin of pterosaurs has been one of the most mysterious paleontological problems since the first discovery of pterosaurs in the late 18th century,” said paleontologist Martin Ezcurra of the Argentine Natural History Museum in Buenos Aires, lead author of the study in the journal Nature. .

The oldest known pterosaurs appeared in the fossil record some 220 million years ago, with a fully developed anatomy for flight, including wings formed by membranes extending from the ankle to an extraordinarily elongated fourth finger.

Also read: Largest flying animal identified in history: Study

The researchers studied the newly discovered and recently excavated fossils using advanced scanning technology and three-dimensional modeling, and identified at least 33 skeletal features that suggest an evolutionary relationship between bearing holes and pterosaurs. This includes the shape of the inner ear, brain sacs and teeth, as well as similarities in the bones of the hands, feet, ankles and pelvis.

“We show that lagerpetids are the closest known pterosaur family and bridge the anatomical gap between pterosaurs and other reptiles,” Ezcurra added.

Lagerpetids also appear to be closely related to dinosaurs, the researchers said. The oldest known dinosaurs were around 233 million years ago. The pterosaurs disappeared 66 million years ago in an asteroid impact that also destroyed the dinosaurs.

Although initially relatively small, the pterosaurs eventually reached enormous dimensions, with a wingspan of 10.7 meters.

“We have studied over the last 50 years how birds have transformed their bodies for flight, and to a large extent this has been supported by extraordinary ancient bird and dinosaur fossils,” said Virginia Tech paleontologist and study co-author Sterling Nesbitt. “Pterosaurs haven’t experienced a revival of this understanding because we don’t have the fossils.”