Washington. A group of paleontologists announced Thursday the discovery of a new species of giant carnivorous dinosaur that had a huge head and tiny arms, like the tyrannosaurus rexand who lived in Argentine Patagonia.
The finding, published in the journal Current Biologysuggests that the small forelimbs of these predators were not an evolutionary accident, but rather gave them certain survival advantages.
Meraxes Gigasnamed after a fictional dragon in the series game of Thrones, was unearthed during excavations and field work carried out over four years in the northern area of Argentine Patagonia. The skull was the first to be discovered, in 2012.
“We won the lottery and found it the first morning,” lead author Peter Makovicky of the University of Minnesota told AFP.
The fossilized remains were remarkably well preserved. The skull measures just over 127 centimeters, while the entire animal would have been nearly 11 meters (36 feet) long and weighed four metric tons. His arms measured 0.60 meters (two feet).
Meraxes Gigas It belongs to “a group that we already know, the carcharodontosaurids. They are the largest carnivores that existed. But until now we did not have a complete skull,” Argentine paleontologist Sebastián Apesteguia told AFP, who presented a replica of the skull on Thursday in Buenos Aires. dinosaur.
The importance of this finding lies in the fact that “we can finally close the true size of the skull, the arm, the legs. It is essential to understand the evolution of this lineage,” added Apesteguia.
M. Gigas it went extinct 20 million years before T. rex arose, and the two species were far apart on the evolutionary tree.
Instead, the authors believe that the fact that tyrannosaurids, carcharodontosaurids, and a third species of giant predator called abelisaurids developed tiny arms is because they derived certain benefits.
Makovicky thinks that their heads, as they grew, became the dominant tool in their predatory arsenal, taking over the role that forelimbs would have had in smaller species.
Juan Canale, project leader at the Ernesto Bachmann Paleontological Museum in Neuquén, Argentina, and co-author of the study, went further, suggesting other advantages.
arms for mating
“I am convinced that those proportionally small arms had some kind of function. The skeleton shows large muscle attachments and fully developed pectoral girdles, so the arm had strong muscles,” he said in a statement.
“They may have used their arms for reproductive behavior, to hold the female during mating, or to hold on to her feet after a rest or fall.”
The Meraxes existed 90 million to 100 million years ago, during the Cretaceous, in a region that was wetter, more forested and much closer to the sea, Makovicky said.
The specimen found lived around 40 years old, a ripe age for dinosaurs, and its skull was full of ridges, grooves, bumps and small horns.
“It certainly would have looked very imposing and gargoyle-like,” Makovicky said.
#species #dinosaur #discovered #Argentina
