Paleontologists announced on Thursday that they have discovered the remains of a new giant dinosaur in Argentina, characterized by its huge head and tiny arms.
Named Meraxes gigas after a dragon in the Game of Thrones series, this carnivorous predator was discovered during excavations conducted over four years in northern Argentine Patagonia. The skull was first found in 2012.
“We won the lottery, we discovered it on the first morning,” of digging, Peter Makovicky of the University of Minnesota in the United States told AFP.
The skull measured more than 1.20 meters and the animal more than 10 meters, with a weight of about four tons. But its upper limbs were no longer than 60 centimeters, “more than half the skull”, and the animal could not use them to “reach its mouth”, specifies the researcher.
The team of scientists, who have published the results of their research in the journal Current Biology, believe the small size of the arms gives the animal some survival advantage.
According to Makovicky, as they grew in size, the head became the dominant tool in their predatory arsenal, taking over the function that the upper limbs served in smaller species.
Juan Canale, co-author of the study and project leader at the Ernesto Bachmann Museum in Neuquén, southern Argentina, goes even further.
“I am convinced that these proportionally reduced arms had a function. The skeleton shows significant muscle attachments and fully developed pectoral girdles, so the arms were strongly muscled,” he said in a press release.
“They could use their arms for reproductive behavior, such as holding the female during mating or supporting themselves to get up after a pause or a fall.”
The merax lived on Earth 90 to 100 million years ago, during the Cretaceous period, when the region was wetter, more forested and much closer to the sea, Makovicky points out.
They could live up to forty years, an advanced age for dinosaurs. Presumably they hunted live sauropods at the same time, the remains of which were discovered at the excavation site.
With a skull full of ridges, grooves, bumps, and small horns, Meraxes “definitely looked very imposing, he looked like a gargoyle,” says Makovicky.
“These are the types of traits that are often subject to sexual selection in living animals,” the researcher points out, specifying that these species used their massive skulls as “billboards” to get noticed by potential mates.