With the discovery of a 240-million-year-old Megachirella wachtleri fossil that was found hidden in the Dolomites in Italy, scientists have now recovered what is believed to be the oldest known lizard fossil in existence.
While the lizard fossil can’t technically be counted as a direct relative of the snakes and lizards that you see around you today, once upon a time they all did have one ancestor in common, and this ancestor scuttled over the Earth around 260 million years ago, as ABC reports.
One of the greatest things about the discovery of the Megachirella lizard fossil is that it proves that lizards and snakes survived the mass extinction that killed off the dinosaurs, and also that lizards came into being long before what has been called the Great Dying, as paleontologist Alessandro Palci explained.
“Many people thought lizards evolved after the mass extinction. It seems now that lizards were already around before the mass extinction and survived, then took advantage of the fact that there weren’t many competitors around and diversified.”
The fossil of the ancient Megachirella lizard was first discovered in 1999, with the lizard remains measuring approximately six centimeters in length. Scientists found that the creature’s ribs, spine, front limbs, and skull were still attached to the skeleton, and over the next 10 years the fossil was closely studied and scrutinized by scientists.
It was the evolutionary biologist Tiago Simoes who decided to look more closely at this tiny reptilian skeleton, and researchers were able to get a much better picture of the fossil by using a 3-D micro-CT scan.
Paleontologist Christy Hipsley has noted that this particular form of 3-D scanning is not only non-invasive but that it has the amazing ability to allow scientists to fully explore areas of fossils that they wouldn’t ordinarily be able to observe.
“A lot of interesting features on fossils are on the inside, but you can’t see them because they’re embedded in the rock. With micro-CT, suddenly you can ‘flip’ the fossil over out of its rock.”
The new dating of this Megachirella means that lizards evolved more than 75 million years before they were first thought to have existed, according to Dr. Palci. Unfortunately, however, the Megachirella has no relatives alive and roaming the Earth today.
“It pushes the origin of lizards back 75 million years. People tend to say Megachirella was the ‘mother of all lizards’ because it sounds very cool, but it went extinct.”
As it turns out, the Megachirella is the ancestor of squamates, which is the class that both snakes and lizards belong in now. Scientists have now determined that when it comes to lizards, geckos are one of the very first of the squamates to have evolved.
You can read more about the discovery of the oldest known lizard fossil known as the Megachirella in the new study that has been published in Nature.