Paleontologists Confirm a Reptile Fossil is the Ancient 'Mother of All Lizards'

Wednesday, 30 May 2018 - 6:41PM
Earth
Wednesday, 30 May 2018 - 6:41PM
Paleontologists Confirm a Reptile Fossil is the Ancient 'Mother of All Lizards'
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YouTube/MUSE Museo delle Scienze
At first glance, the reptile Megachirella wachtleri pictured above looks like a normal lizard. And it should - it's the direct ancestor of nearly every lizard we know of today.

An international team of researchers have recently been poring over a Megachirella fossil found back in 2003, and have now been able to confirm that the species is the oldest known lizard, which lived 240 million years ago during the Triassic period. Around 10,000 species of modern lizards and snakes are descendants of this little chameleon-sized fellow, and they've had some time to branch out since then.

The fossil was first uncovered in the Dolomites mountain range in Italy, but back when the species was alive, it roamed through the single supercontinent Pangea while the dinosaurs were still recent additions to the prehistoric animal kingdom. Reptiles had existed before then (many died in a mass extinction event 10 million years prior), but Megachirella is the first known instance of a "squamate", the largest order of reptiles that includes lizards and snakes.



This Megachirella fossil thus pulls our evolutionary timeline of lizards back by 75 million years, since there was no prior evidence that any were alive back then. When first found, it was thought to belong to a different "lepidosaur" reptile, but the team of researchers examined its distinctive lizard like features (the shape of its tiny jaw was a major clue) and ran some more detailed tests including CT scans to see what exactly had been dug up.

After these detailed scans and several trips to over 50 museums, the team - led by Tiago Simoes of the University of Alberta, a co-author of the study they published in Nature - could say with certainty that this Megachirella was the common ancestor of all known modern squamata, otherwise known as the "mother of all lizards".  

It's always fascinating to see missing links in the evolutionary chain filled in like this, and it's also cool to see what sort of critter eventually paved the way for iguanas, geckoes, snakes, etc.

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