This once-forgotten fossil holds the key to lizard evolution


A new discovery in the UK is a triumph for those who love chaos and organization.

An ancestor of today’s lizards, first discovered in the 1950s, was recently found in a cupboard at the Natural History Museum in London. This discovery suggests that today’s lizards originated first Late Triassic (about 200 million years ago) and not at this time Middle Jurassic as previously believed.

[Related: A Scottish fossil is helping scientists fill the gaps in the lizard family tree.]

The results of the study are described in the paper magazine published today Scientific progress. The team named the discovery Cryptovaranoides microlaniusit means “small carnivore” and is a tribute to the animal’s jaws filled with sharp cutting teeth.

“I first saw the sample in a drawer full of drawers Klevosaurus Fossils in storage at the Natural History Museum in London, my research fellow,” said David Whiteside, a scientist at the University of Bristol’s School of Earth Sciences. in the statement. “It’s a close relative of New Zealand’s tuatara, the only surviving species from a group called Rhynchocephali, which split off from the shells more than 240 million years ago, and was a common enough fossil.

The specimens were first found in a quarry in southwest England.

“Our sample was just written”Klevosaurus and another creeper.’ As we continued to study the specimen, we became increasingly convinced that it was more closely related to modern lizards than to the Tuatara group.” Whiteside added. “We did x-rays at the university, which reconstructed the fossil in three dimensions and allowed us to see all the tiny bones that were hidden inside the rock.”

The age of the new find affects the general estimate of when Squamata, an order of reptiles This includes how lizards and snakes evolved, how quickly they evolved, and even the factors that triggered the overall origin of the order.

Research shows this Cryptouranoids It is clearly in contact due to many features, including the cerebellum (which covers the brain), the cervical vertebrae, the upper middle teeth in the front of the mouth, and the placement of the teeth on the mandibular shelf. It is also characterized by an opening on one side of the end of the upper arm bone, a foramen through which nerves and arteries pass, and a small number of teeth that form the roof of the bone. lizard’s mouth

[Related: These tiny ‘dragons’ flew through the trees of Madagascar 200 million years ago.]

“In terms of importance, our fossil record goes from the Middle Jurassic to the Late Triassic,” said Mike Benton, a palaeontologist at the University of Bristol. in the statement. “This was a time of great structural change in terrestrial ecosystems, with the emergence of new plant groups, especially modern conifers, as well as new types of insects, turtles, crocodiles, and dinosaurs. and mammals.

The addition of pre-modern squamates will help complete this evolutionary picture after Earth’s re-creation. End-Permian mass extinction252 million years ago, about 95% of the world’s marine species and 70% of land species were wiped out.

“The name of the new animal, Cryptovaranoides microlaniusThis reflects the hidden nature of the beast in the drawer and suggests a lifestyle that may have lived in the limestone crevices of the small islands around Bristol at the time,” said the University of Bristol. in the statement.





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