Scientists in Buenos Aires have unveiled a new species of dinosaur related to the giant Tyrannosaurus, the smaller Velociraptor and existing birds.
Officials from the Argentine Museum of Natural Science dubbed the prehistoric creature Bicentenaria Argentina.
Researchers said the carnivorous beast was likely to be measured between 2.5 and 3 metres (8 and 10 feet) long and was slim and agile.
Palaeontologist Fernando Novas said the dinosaur represents a new line line leading to the evolution of modern day birds. Novas said:
The Bicentenaria isn't one of the biggest dinosaurs, it is approximately 2.50 metres (8 feet) long, but it is part of a group that ends up with the origins of gigantic creatures like Tyrannosaurs and others that aren't so big like the Velociraptor and ultimately those feathered dinosaurs with long arms but that are actually quite small which are birds.
This means that the Bicentenaria is a distant ancestor that at the end of the bridge leads to birds. So we are seeing the great great grandfather of birds
The shape of its sharp curved teeth and its long claws suggest Bicentenaria hunted other smaller dinosaurs, the scientist said.
The bones were discovered in Rio Negro in Argentina's Patagonia region and are thought to be approximately 90 million years old.