Fossil from 240 million years ago reveals “mother of all lizards”

A 240-million-year-old fossil has been identified as the ancestor of all lizards and snakes. The team of scientists who described the “mother of all lizards” includes Dr. Mateusz Talanda of the University of Warsaw.

The bones of the small creature, whichóre flowed out of the sea about 240 millionóyears ago off the coast of present-day Italy, turned out to be the oldest known fossil of a lizard. It is the direct ancestor of some 10,000 species currently livingów.

Species Megachirella wachtleri was described in 2003. However, researchers were not inóat the time sure howób new species fits into the family tree of reptilesów. This has been helped by recent research, whichóre revealed hitherto unknown features of the fossils, allowing scientists to identify the Megachirella wachtleri, as the oldest known ancestor of the scaly – row in the reptile clusteróin, to whichórego belong to lizards or snakes.

CoóThe early scaly ones are very zróA diverse group and have a long evolutionary history. Between the oldest fossils found and their estimated origin, there was a gap of about 70 millionóin years. A little more light was shed on these issues by a publication in the journal „Nature”. A group of scientistsóin whichóhe composition also included a Polish paleontologist, describes the results of his research using high-resolution computed tomography data of the fossil specimen Megachirella wachtleri.

Genetic evidence had already indicated to the researchers that the ancestor of the lizards appeared during the Permian period – more than 250 millionóin years. But the oldest known fossil was about 70 millionóIn years younger. – That’s more time than between us and the dinosaurs and we had no idea what was going on – admitted Tiago Simões, a paleontologist at the University of Alberta.

– Understanding the evolution of the lizard and snake is an ongoing problem in paleontology. The trouble largely stems from the lack of suitable fossils. Bones of a giant dinosaurów are fairly easy to find, but if you are looking for something that can fit in the palm of your hand, it is extremely difficult – said Stephanie Pierce of Harvard University, który studied the remains Megachirella wachtleri in 2003.

Photo. MUSE – Science Museum, Trento

The fossil was found nearly 20 years ago in the Dolomites in Italy, które once found underwater. However, the first study misclassified the remains of the creature. The fossil is partially embedded in rock, which obscures some of theóre of its distinctive features. The features were revealed after examination using CT scans.

The analysis showed previously unknown detailsós pertaining to the palate, skull and limbs, whichóre are unique to lizards. Scientists also found evidence of residual features, które lost wspóLately living scaly – involved a small cheekbone and someóre abdominal bones occurring rów also in many dinosaursów.

The research, conducted at Megachirella wachtleri were combined with new measurements of specimensóin those found from China to Brazil along with their DNA studies. In this wayób scientists reconstructed the evolutionary tree of the scaly.

– With this very extensive data set, it became possible to truly estimate the affinities of this species with other reptile speciesów – said Simões.

Megachirella wachtleri was a small, terrestrial animal with teeth suitable for grasping insectsów. He walked the Earth at a time when only one continent still existed – Pangea. The new identification helps explain the transition from more primitive reptilesów to a large, zróof the diversified order of scaly.

– It’s like the Rosetta Stone in terms of the information it gives us about the evolution of snakes and lizards – said Michael Caldwell of the University of Alberta, współautor of the study.

A member of the team of researchers whoóers responsible for publications in „Nature” is the aforementioned Dr. Talanda. – When I viewed the specimen Megachirella wachtleri, I came to the conclusion that it has characteristics of lizard-like. It later turned out that three more researchers, from Italy and Canada, independently came up with the same idea. Instead of competing, we decided to join our forces – said in an interview with „Gazette” scientist.