AFP, Published on Wednesday 04 May 2022 at 11:41 am
Three years after its discovery in southern Argentina, a dinosaur fossil is gradually revealing its secrets: 70 million years old, 10 meters long, it was a large predator that unleashed its prey using sharp, curved claws.
The remains of this “megarapt”, a sarcophagus dinosaur with large hind legs and small upper limbs, were discovered in March 2019 in the south of the province of Santa Cruz in Patagonia, 30 kilometers south of the tourist town of El Calafate.
Mauro Aranciaga, a 29-year-old paleontologist working in the Comparative Anatomy Laboratory at the Museum of Natural Sciences in Argentina, directed by Fernando Novas, discovered the first part of the skeleton while participating in his first excavation campaign in 2019.
“When I lifted the vertebra I saw that it had the characteristics of a megaphone. “It was really a huge feeling, I saw a huge vertebra and that meant we were dealing with a giant magician,” recalls the young researcher.
“I made a childhood and adult dream come true!” told the French Agency at the laboratory facility in Buenos Aires.
Three years later, after a tedious task of extracting, transporting, cleaning and many months of laboratory studies, the first conclusions about “Maip macrothorax”, its name, have just been published in the scientific journal Nature.
“It was a large animal, according to the measurements and comparisons we made (…) It is also one of the last giants to have lived on the planet before the extinction of the dinosaurs, about 66 million years ago,” explains Fernando Novas . , the director of the laboratory.
– Chop the prey –
This Argentine paleontologist has a long history of discoveries behind him.
In 1996, he found the remains of the first representative of the megaraptor group 1,400 kilometers away, in the province of Neuquen (south).
Others were later discovered in Australia, Thailand, Japan, he says.
Away from the titanosaurs, the largest known dinosaurs, which can measure about thirty meters and weigh 70 tons, the giants mentioned so far were between 8 and 9 meters long.
“It was between 9 and 10 meters long and weighed about 6 tons,” explains Mauro Aranciaga, the largest known magnate maker to date, who also points out that he was “at the top of the food chain” in his ecosystem.
Several vertebrae, ribs, hip, tail and arm pieces were found.
The researchers were also “surprised to find that the megaraptors had huge claws on their thumb and forefinger.
“They had three fingers on their hands, but their fingernails were about forty centimeters long,” says Novas.
“Obviously, these claws were going to be used to capture prey, tear them apart and search their entrails,” he added.
Hence his baptismal name: “Maip” is a word Tehuelche, an indigenous people of southern Argentina, referring to an evil spirit or “the shadow that death leaves behind”.
As for his chest, it was up to 1.20 meters wide and 1.50 meters long, according to the researchers.
“Maip had such a large chest that the interference of the ligaments connecting the vertebrae to the ribs was preserved. This allows us to go a little further and reconstruct parts that are not usually preserved,” explains Mauro Aranciaga.
Fernando Novas says the discovery was made in an “extraordinary deposit that proves to be one of the most important in South America”. It dates from the Cretaceous (-145 to -66 million years) “when there were neither the Andes nor the glaciers, but rather tropical forests in which a large variety of animals lived”.
The first signs of the presence of fossils in the area appeared in 1980 thanks to the work of Argentine geologist Francisco Nulo, but the first real campaign was launched in 2019 by the team of Fernando Novas.