BUENOS AIRES: Researchers announced on Thursday they have discovered a ferocious meat-eating dinosaur in Argentina, notable for having short arms like the T-rex but hailing from a different branch of the family tree.

The Gualicho shinyae — nicknamed Gualicho — is a theropod, a two-legged, bird-like dinosaur. It stretched an imposing six meters (nearly 20 feet) from head to toe, and weighed an estimated 450 kilograms (1,000 pounds).

It roughly resembles the Tyrannosaurus rex but Gualicho, found in the north of Argentina’s Patagonia region, was not a close relative of the king of dinosaurs.

Its stubby limbs evolved independently and not from a shared, short-armed ancestor — a clue that may help researchers better understand how the extinct animals evolved.

“This is a completely different lineage. We just froze up when we realised it,” Sebastian Apesteguia, a researcher at Argentina’s National Scientific and Technical Research Council told a briefing in Buenos Aires.

Its only known ancestor is the Deltadromeus, a leggy, carnivorous dinosaur with slender arms found in Niger.

The new dinosaur’s name Gualicho is in honour of a local indigenous diety with power over animals and the wind. And Shinyae is in honour of Akiko Shinya, chief fossil preparator at Chicago’s Field Museum, who found the incomplete skeleton while working on the dig.

“We found Gualicho at the very end of the expedition. Pete joked, ‘It’s the last day, you’d better find something good!’ And then I almost immediately was like, ‘Pete, I found something.’ I could tell right away that it was good.” She was referring to Peter Makovicky, The Field Museum’s curator of dinosaurs.

“Gualicho is kind of a mosaic dinosaur, it has features that you normally see in different kinds of theropods,” Makovicky said in a statement.

Published in Dawn, July 15th, 2016