AFP, published on Wednesday, May 04, 2022 at 11:41 am
Three years after its discovery in southern Argentina, the fossil of a dinosaur is gradually revealing its secrets: 70 million years old, measuring 10 meters in length, it is a huge predator releasing its prey using sharp, curved claws.
The remains of this “megaraptor”, a carnivorous dinosaur with large hind legs and small upper branches, were discovered in March 2019 in the southern province of Santa Cruz in Patagonia, 30 km south of the tourist town in El Calafate.
Mauro Aranciaga, a 29-year-old paleontologist working in the Comparative Anatomy Laboratory of the Museum of Natural Sciences in Argentina, led by Fernando Novas, discovered the first piece of skull while participating in his first excavation campaign in 2019.
“When I looked at the vertebra I saw that it had the characteristics of a megaraptor. It was a huge emotion, I saw a giant vertebra and that meant we were dealing with a giant megaraptor”, recalls young researcher.
“I realized a dream of childhood and adulthood!” He told AFP at the laboratory site in Buenos Aires.
Three years later, after a tedious job of extraction, transportation, cleaning and long months of laboratory studies, the first conclusions about “Maip macrothorax”, its name, were recently published. in the scientific journal Nature.
“It is a large animal, according to the measurements and comparisons we have made (…) It is also one of the last megaraptors to live on the planet before the extinction of the dinosaurs, about 66 million years ago. passed ”, explained Fernando Novas, the director of the laboratory.
– Cut the victim –
This Argentinian paleontologist has a long history of discovery behind him.
In 1996, he found the bodies of the first representative of the megaraptor group 1,400 km away, in the province of Neuquen (south).
Some were immediately discovered in Australia, Thailand, Japan, he said.
Far from titanosaurs, the largest known dinosaurs, which can measure about thirty meters and weigh 70 tons, the megaraptors currently listed are measured between 8 and 9 meters in length.
“This one measured between 9 and 10 meters in length and weighed about 6 tons”, the largest of the megaraptors known to date, explains Mauro Aranciaga, who also points out that he “is in top of the food chain ”in its ecosystem.
Several vertebrae, ribs, thighs, tail and arms were found.
The researchers “were also shocked to discover that megaraptors have large claws on their thumb and forefinger.
They have three fingers on their hands, but their nails are about forty centimeters long, ”Novas said.
“Obviously, these nails should be used to catch the prey, tear them apart and dig into their intestines,” he added.
Hence its baptismal name: “Maip” is the word Tehuelche, an indigenous people of southern Argentina, referring to the evil spirit or “the shadow left by death after its passing”.
As for his thorax, it measured up to 1.20 meters wide, for 1.50 meters long, according to the researchers.
“The Maip has a large thorax that the insertions of the ligaments that connect the vertebrae to the ribs are preserved. This allows us to go a little further and rebuild the parts that usually not preserved ”, explained Mauro Aranciaga.
Fernando Novas says the discovery took place in a “unique deposit that has become one of the most important in South America”. It dates from the Cretaceous (-145 to -66 million years) “before the Andes or the glaciers, but tropical forests where a large diversity of animals lived”.
The first signs of the presence of a fossil deposit 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 Fernando Novas ’team.