(Santiago de Chile) Chilean paleontologists presented the results of their research on Stegouros elengassen on Wednesday, a dinosaur whose skeleton was discovered almost intact three years ago in Patagonia (south) and which baffles scientists by its tail.
The dinosaur was discovered during excavations in 2018 at Cerro Guido, a site known to harbor numerous fossils, by a team who believed they were dealing with an already known type of animal until the remains of its tail appeared. surprising.
“It was the main surprise […] This structure is absolutely amazing, ”said Alexander Vargas, one of the paleontologists, during the presentation of the find at the University of Chile.
“Because the tail was covered with seven pairs of osteoderms […] producing a weapon absolutely different from anything known for any dinosaur, ”added the researcher.
PHOTO IVAN ALVARADO, REUTERS
Paleontologists have discovered 80% of the dinosaur’s skeleton and estimate that the animal lived in the area 71 to 74.9 million years ago.
Osteoderms – bony plaque structures located in the dermal layers of the skin – are aligned on either side of the tail and make it look like a large fern.
Paleontologists have discovered 80% of the dinosaur’s skeleton and estimate that the animal lived in the area 71 to 74.9 million years ago. It was about two meters long, weighed 150 kilograms and was herbivorous.
According to the scientists, who published their research in the specialized journal Nature, it could represent a hitherto unknown lineage of an armored dinosaur never seen in the southern hemisphere, but already identified in the north of the continent.
“We don’t know why (the tail) evolved. We know that within armored dinosaur groups there seems to be a tendency to independently develop different defense mechanisms based on osteoderms, ”explained Sergio Soto, another member of the team.
The Cerro Guido area, in the Las Chinas valley 3000 km south of Santiago, stretches for 15 km. Various rock formations outcrop there, which contain many fossils.
It is “a kind of book that allows us to understand the successions of flora and fauna in this place”, explain the paleontologists.
It also allowed them to discover that present-day America and Antarctica were close millions of years ago.
“There is strong evidence that there is a biogeographical link with other parts of the planet, in this case Antarctica and Australia, because we have two closely related armored dinosaurs there” at Stegouros, Sergio clarified. Soto.