Oldest known lizard discovered: Why is the tiny reptile so unique?

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A global group of paleontologists, which includes the University of Bristol, has discovered a 240 million-year-old reptile's fossil remains which prove that it was actually the mother of all lizards.

Lizards and snakes belong to a family of animals called squamates, and today there are nearly 10,000 different species slithering around the world's deserts, backyards, forests and mountains.

The conditions under which the fossil was found - in marine sediments but surrounded by fossilized land plants - suggest that a powerful storm hit the coastline where megachirella lived and swept the tiny critter out to sea.

With the latest CT scan technology, scientists able to study fossil's arm, wrists, clavicle, and skull. Tiago Simões, a Ph.D. candidate in biological sciences at the University of Alberta and the lead author of the study employed advanced microfocus X-ray computed tomography imaging to study the fossil belonged to Megachirella Wachtleri specimen.

There are about 10,000 species of squamates around the world, and scientists say they are still learning about the early stages of the animals' evolution.

For Simoes, the study is about more than the history of lizards.

Originally found in the early 2000s in the Dolomites Mountains of Northern Italy, researchers considered it an enigmatic lizard-like reptile but could not reach conclusive placement, and it ramained almost unnoticed by the worldwide community.

"When I saw the fossil for the first time, I realized that some of its characteristics could be the closer of the first lizards", explains the researcher.

Her name was Megachirella wachtleri. Simoes stated that he spent around 400 days by visiting more than 50 museums and university collections in across 17 countries to evaluate the specimens to get an idea about the evolution of reptiles and lizards. But the oldest known squamate fossil was about 70 million years younger than that. But it seems that some specimens of dinosaurs and lizards survived and then diversified into different types of species.

Simoes' colleague and study co-author Michael Caldwell likened the Megachirella fossil to "a virtual Rosetta Stone in terms of the information it gives us on the evolution of snakes and lizards".

Previous studies on lizard fossils dated back the fossils to 75 million years ago. But some parts of the fossil, like the knee, ankle and key lizard features are missing in the study and it is quite disappointing.

Researchers from the U of A, Australia, Italy and the United States worked on the analysis leading up to this discovery.