These little reptiles are relatives of the pterosaurs

These little reptiles are relatives of the pterosaurs

After analysing fossils discovered more than a century ago in the northeast of Scotland, paleontologists established a link between the little creatures that developed 237 million years ago and the famous pterosaurs.

Tens of millions of years before the first birds appeared, the pterosaurs pioneered their flight using sail-like wings and super-light bones, but the origins of these creatures are still largely unclear, mainly because of the lack of fossils. The earliest known pterosaurs had wings and were capable of flying, making it difficult to map their air evolution.

In a recent study, scientists from Birmingham University and the Virginia Institute of Technology may have discovered the Earth's origin of these ancient creatures, re-examining fossils found more than a century ago in a sandstone in northeast Scotland.

Known as the Elgin reptiles, in honor of the nearby Scottish city, fossils date back about 237 million years, which refers to a late triasal period, which represents a species called Skleromochlus. These creatures were not very large, barely 20 centimetres long.

Since its discovery in the early 1900s, Skleromochlus has been perplexed by paleontologists, as many of his bones have been lost, leaving only a few fingerprints in the rock. For a long time, researchers have poured latex or wax into these blanks to create blinds. This technique works, but it does not reveal the most difficult features.

For the new work, paleontologists placed several such sandstone blocks containing samples of Skleromochlus under a microtomograph, allowing them to reconstruct the skeleton of this extinct species in three dimensions in digital format.

In close examination, researchers identified several features that Sclairmochlus shared with Lagerpetids, a group of small reptiles that evolved in a triaxial period, including an unusually large skull and a hooked femur head that fit vertically into the thigh rather than parting as a leg.

Lagerpetids appeared to be small, mobile, two-legged creatures close to dinosaurs, but even closer to pterosaurs. ", says Dr. Brousatta, the lead author of the study. "

If Skleromochlus was indeed an early relative of the pterosaurs, then this calls into question the hypothesis that the pterosaurs were originally adapted for planning. As Kevin Padian, who studied the evolution of the pterosaurs for decades, did not have strong hips to jump from branch to branch, so he was clearly not adapted to life on trees.

Instead, Skleromochlus probably felt more comfortable on the ground chasing bugs with free forearms, potentially preparing the ground for what should happen. The use of their fore limbs for other functions could indeed be linked to the evolution of new habits, including active flight in the case of pterosaurs.