A team of scientists in Argentina says they’ve discovered a new species of predatory dinosaur that has a giant head but arms that are too small for their size. The discovery could help unravel why the famous Tyrannosaurus rex had short arms.

In an article in the academic journal Current Biology, scientists say skeletal remains of the new previously unknown dinosaur have been found in northern Patagonia.

Nicknamed Meraxes gigas, he was 11 meters long, had a 1.2-meter skull, but his arms were only 60.9 centimeters. Scientists believe the short arms give this carnivorous animal advantages for survival.

“I was convinced that these proportionally smaller arms had some kind of functionality. The skeleton shows large muscle attachments and fully developed chest structures, so the arms had strong muscles,” said Juan Canale, lead author of the study.

“They may have used their arms as a support for reproductive behavior, to hold the female during intercourse, or to rest or get up after a fall,” he said.

Co-author of the study, Peter Makovicky, said the dinosaur’s arms were “literally half the length of its skull and could not reach the mouth of the animal with its hands.”

Makovicky says he believes this species’ massive head was the main predatory vehicle, taking on functions played by arms in smaller dinosaurs.

Meraxes gigas, named after the dragon in the fictional TV series game of Thrones Does (Game of Thrones) belong to the genus Carcharodontosaurs? Latin-inspired name for “shark-toothed lizards.”

The four-ton reptile would have lived on Earth about 90 to 100 million years ago. Two other species, such as tyrannosaurs (which includes Tyrannosaurus rex) and abelisaurs, also had short arms for similar reasons, the scientists say.

– Originally published text https://www.bbc.com/portuguese/geral-62069618