Paleontologists announced on Thursday that they had discovered the remains of a new giant dinosaur in Argentina, remarkable for its enormous head and small arms.
Baptized Meraxes gigas — after a dragon featured in the Game of Thrones series — this carnivorous predator was discovered during four-year excavations in northern Argentine Patagonia. The skull was found first, in 2012.
“We won the lottery, we discovered it on the first morning” of excavations, explained to AFP Peter Makovicky of the University of Minnesota, USA.
The skull measured more than 1.20 meters, and the animal more than ten meters, for a weight of about four tons. But its upper limbs were no longer than 60 centimeters “being half the skull” and the animal could not use them to “reach its mouth”, says the researcher.
L he team of scientists, who published the results of their research in the scientific journal Current Biology, believe that the small size of the arms gave the animal a certain advantage in surviving.
According to Makovicky, as the head grew in size, it became the dominant tool in their predatory arsenal, taking over the function the upper limbs had in smaller species.
Juan Canale, co-author of the study and project manager at the Ernesto Bachmann Museum in Neuquen, southern Argentina, goes even further.
“I am convinced that these proportionally reduced arms had a function. The skeleton shows significant muscle insertions and fully developed pectoral girdles, so the arms had strong muscles,” he explained in a statement.
“They could use their arms for their reproductive behavior, such as holding the female during mating or supporting themselves to get up after a break or a fall.”
The Meraxes lived on Earth there 90 to 100 million years ago, during the Cretaceous, when the region was wetter, more forested and much closer to the sea, Makovicky points out.
They could live up to forty years old, an advanced age for dinosaurs. They presumably hunted sauropods living at the same time, the remains of which have been discovered at the excavation site.
With his skull full of ridges, furrows, bumps and small horns, Meraxes “had certainly looked very imposing, it looked like a gargoyle,” says Makovicky.
“These are the types of characteristics that, in living animals, are often subject to sexual selection”, underlines the researcher, specifying that these species used their massive skull as a “billboard” to get noticed. by potential partners.