Argentine scientists say they have discovered a giant predatory dinosaur with short arms
A team of scientists in Argentina says they have discovered a new giant predatory dinosaur that had a huge head, but its arms were small compared to its size.
The scientists, who published their findings in the journal Current Biology, said they had discovered large skeletal remains of a previously unknown species in excavations in northern Patagonia.
The length of the dinosaur, known as "Miraxis gigas", was about 36 feet, and the size of its skull was four feet, while its arm length was only about 2 feet.
Scientists believe that the small limbs gave the carnivores a survival advantage.
"I am convinced that those relatively small arms have some sort of function," said Juan Cana, the study's lead author. "The skeleton shows large muscles and a well-developed chest area, so the arm had strong muscles."
"(Dinosaurs) may have used the arms in mating, such as holding the female during mating or supporting herself to stand back when she was subjected to falls or fractures," he added.
Peter Makovsky, co-author of the study, said the dinosaur's arms were "literally half the length of the skull and the animal wouldn't be able to get into its mouth."
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Makovsky said he believed that the dinosaurs' large heads were the main predatory tool, performing functions that the arms would have performed in smaller species.
Named after a fictional dragon in the "Game of Thrones" novels, Miraxis gigas is a member of the carcharodontosaurids , or shark-toothed lizards.
These four-ton reptiles are believed to have roamed the Earth about 90-100 million years ago.
The scientists say that two other species - tyrannosaurs and abelisaurides - also evolved small arms for similar reasons.
https://www.bbc.com/arabic/science-and-tech-62058405