Scientists have identified the world’s oldest lizard – the most most ancient ancestor of all modern lizards and snakes – by analysing a 240-million-year-old fossil. The study, published in the journal Nature, provides key insight into the evolution of modern lizards and snakes. The 240-million-year-old fossil, Megachirella wachtleri, is the most ancient ancestor of all modern lizards and snakes, known as squamates, according to researchers including those from the University of Bristol in the UK.
This discovery took the group back 75 million years and signifies that “lizards have inhabited the planet for at least 240 million years”, said Tiago Simoes, one of the study’s co-authors, from the University of Alberta in Canada.
Enter Megachirella wachtleri, a three-inch, 240-million-year-old fossil – and an exciting new clue in this evolutionary mystery.
A team of worldwide scientists published their findings in the academic journal Nature, which revolved around the chameleon-sized reptile Megachirella wachtleri. Her existence helps explain the transition from more primitive reptiles to the large, diverse order that now slithers, creeps and burrows across every continent except Antarctica.
“When I first saw the fossil I realised it had important features that could link it to the early evolution of lizards”, he said.
“At first I did not think Megachirella was a true lizard, but the empirical evidence uncovered in this study is substantial and can lead to no other conclusion”, co-author Randall Nydam of Midwestern University said in a statement. T
he fossil of the Megachirella was initially discovered near about twenty years ago somewhere in the Dolomites region of northeast Italy. But some parts of the fossil, like the knee, ankle and key lizard features are missing in the study and it is quite disappointing.
Scientists have always been unsure of M. wachtleri’s place in the reptile family tree. Caldwell added that the fossil gave them the information they needed “on the evolution of snakes and lizards”.
The authors of the study stated they have given the paleontological world some kind of Rosetta Stone for reptile evolution and a fair beginning of the evolutionary tree. But today, micro CT scan with a higher resolution, allowed scientists to look inside the rock and see all the features that were inside it. Simões and his colleagues have identified the brain case, collarbone and wrists that make the fossil a lizard.
The team found a tiny bone in Megachirella’s lower jaw that is unique to the squamate family. When megachirella walked the Earth, in the middle Triassic period, the world’s land masses were crushed together in a supercontinent called Pangaea.
“It’s confirming that we are pretty much clueless”. Andre specializes in environmental health, but writes on a variety of issues.