In the spring of 2022, Georgios Georgalis, an associate professor of paleontology at the Academy of Sciences in Krakow, Poland, was invited to France by the University of Montpellier to examine fossils from a large excavation.
The findings had come from Tunisia’s Chambi National Park, and the Montpellier team of paleontologists asked the Greek expert, who specializes in Cenozoic reptiles, to investigate whether he could find any mammals from his own field among the fossils.
“I was very happy to find that there were many reptiles among them,” says Georgalis, describing how he managed to arrive at the discovery of the Terastiodontosaurus marcelosanchezi, a 50-million-year-old lizard, on which he and his colleagues published recently in the Zoological Journal of the Linnean Society.
“Internationally, in our science we choose to give Greek names to the vast majority of the animals we discover. For Greek scientists, this is a special privilege, because we can understand their significance,” Georgalis notes with pride, not only for the name he chose but also for the discovery itself.
“As soon as I saw the Terastiodontosaurus in front of me, it piqued my interest, because it had a very strange morphology. I understood that it belonged to the worm lizards, a group of mysteriously shaped lizards whose skeletal anatomy differs from all other lizards.”
The animal’s very large size, combined with its strange dentition (or arrangement of the teeth), which featured a huge, flattened tooth in the upper and lower jaw, unlike any other worm lizard, made the 41-year-old scientist – who has previously published on other important reptile discoveries – to take great interest in that particular fossil. In fact, he invited his colleagues from the universities of Frankfurt and Montpellier, the National Bureau of Mines of Tunisia and the Museum of Natural History of Paris to collaborate in this study.
Looking at the skull, however, we find that this is very large, so we can say with relative certainty that this is the largest worm lizard.
“We used the latest technology, a kind of small CT scanner that offers full penetration of the fossils. With it we were able to study every detail without disturbing the fossil. We also used modern worm lizards from North Africa to compare skeletons, study musculature and see how hard these reptiles could bite. Our fossil had very impressive jaws and, according to our calculations, this particular reptile had many times the bite force of any other worm lizard. The huge tooth that occupied over 52% of the dentition was used to crush large snails, which were also found as fossils in the area,” he explains.
After two years of detailed study, the team concluded that this particular worm lizard had a larger skull than any other of its species, huge jaws and was more than one meter in size.
“This calculation is not entirely accurate. Legless lizards, such as worm lizards, live underground and for this reason they have a lot of vertebrae, but we cannot count them precisely. Looking at the skull, however, we find that this is very large, so we can say with relative certainty that this is the largest worm lizard.”
Photographs of the upper (left) and lower jaws (right) of the Terastiodontosaurus. [Georgalis et al., 2024]
With the help of a modeling expert, Georgalis and his team breathed life into Terasiodontosaurus, representing the image of the reptile as it was before it became extinct.
“Fifty million years ago coincides with the period of some of the hottest temperatures on the planet. This very warm climate favored large sizes in reptiles. It is indicative that in similar places, in other longitudes and latitudes of the planet, we have found very large snakes and other very large lizards, which makes us believe that something was happening in the climate around 50 to 45 million years ago. Around 45 million years ago we had a drop in temperature and around 40 million years ago this decline became even greater. In a nutshell, we can say that the extinction of the Terastiodontosaurus was due to climatic reasons,” he explains.
Georgalis’ publication of the discovery has attracted the interest of paleontologists who specialize in worm lizards from all over the world. Even the American magazine Newsweek dealt with the discovery of the Greek professor because of the size of the lizard and its characteristics.
The Terastiodontosaurus was not his first publication, however. In Greece, Georgalis has published on other reptiles such as the Laophis crotaloides (2016), which, at more than three-meters long, is recorded as the largest viper on earth, while in 2017 he published on the so-called Komodo dragons, lizards which today live in tropical and subtropical climates and are estimated to have disappeared in Europe about three million years ago.
“I also discovered crocodiles in Crete that lived 9 million years ago and in Evia 18 million years ago. In the same area, in one of my first publications, I found one of the oldest chameleons in Europe, about 16 million years old, which showed us that they could migrate from Africa to Europe in those periods,” he says.
Throughout our conversation, the paleontologist, who is originally from Thessaloniki, spoke enthusiastically about his latest scientific success.
“I have a chemistry degree from the Aristotle University of Thessaloniki, but paleontology has always been my great passion. In Greece I did not manage to find a professional path, because the subject of reptiles is not popular here, so I turned my attention to abroad. In Poland, on the other hand, paleontology is valued. For the last three years I have been living with my family in Krakow, where I now have a permanent position, my own laboratory with all the necessary equipment and a group of students. The Institute of Systematics and Evolution of Animals of the Polish Academy of Sciences provides me with significant support to excavate and study the material, while also providing me with funds to attend conferences, traveling from the North Pole to America to Central and Southern Europe,” he says.
Georgalis has worked as a paleontologist in Zurich, Turin, Bratislava and Slovakia. He is currently preparing to study the new material between 50 and 30 million years old that he has at his disposal from Tunisia and France, with the aim of reaching the next great discovery.
