Scientists have unearthed something strange in Argentina: A fossil from a two-legged carnivorous dinosaur with a big body, but tiny arms just like the Tyrannosaurus Rex.

According to the study published in the journal PLOS ONE, the strange meat-eating reptile is called Gualicho shinyae. Gualicho is from a spirit revered by the Tehuelche in Patagonia called "Gualichu," while shinyae is derived from the famous discoverer Akiko Shinya.

Standing at an estimated 20 to 26 feet, the Gualicho shinyae is a bipedal theropod that features very short forelimbs at about two feet, with each arm having two fingered claws.

"Something totally new has been discovered, a new lineage that we didn't know of before," said palaeontologist Sebastian Apesteguia in a conference, as quoted by The New York Times

Gizmodo notes that even though it has similar features with the T. rex, it is totally unrelated to it.

Belonging to a different family tree means that the Gualicho shinyae's physical features evolved independently through parallel evolution along with other dinosaur species.

“Gualicho is kind of a mosaic dinosaur, it has features that you normally see in different kinds of theropods,” said Peter Makovicky, co-author of the study.

He notes the newly discovered species is unique and does not fit with other categories of carnivorous dinosaurs. However, further studies are needed to know the reason behind the Gualicho's small arms and similarity with the T. rex.

"Why did this species have a reduction regarding the size of their arms, having only two fingers similar to a Tyrannosaurus? That's something that we still don't know. But we need to investigate it," Apesteguia said.