Researchers in Argentina have unearthed a stunning discovery: a new species of dinosaur, a giant predator with the teensy arms similar to the ones Tyrannosaurus rex is famous for. A remarkably complete fossil of the dinosaur was found in the northern Patagonia region, with paleontologists estimating that it weighed more than four tons and stretched 11 meters from nose to tail, according to a study published Thursday in the journal Current Biology. The previously unknown species has been named Meraxes giga, after one of George R.R. Martin’s dragons in the Song of Ice and Fire series. Meraxes lived 90 million years ago during the Cretaceous period and had “no direct relation” to T. rex, which began walking the planet 20 million years later. Like T. rex, scientists are stumped as to the purpose of Meraxes’ arms, given that the huge carnivores more likely used their big heads to kill their prey. But its nearly complete forelimb was strangely muscular, according to Juan Canale, the lead author of the paper. To Gizmodo, he quipped: “The function of those tiny arms is very, very difficult to know. We need a time machine.”