A newfound species unearthed in Brazil is the oldest long-necked dinosaur ever discovered.

Three 'exceptionally well-preserved' dinosaur skeletons dug up in Rio Grande do Sul are estimated to have walked the Earth 225 million years ago.

The species, known as Macrocollum itaquii, was vegetarian, stood at around 12 feet long and five feet tall, and weighed around 200 pounds.

One of the most striking features of animal was its long neck - and scientists now believe it to be the oldest long-necked sauropodomorpha ever discovered.

Its 'remarkably elongated' neck would have 'provided a competitive advantage' when gathering food resources, a report published Royal Society journal Biology Letters said.

The species would have existed on Earth during the Triassic period, when Brazil was still a part of super-continent Pangaea.

The dinosaur is also a distant cousin of sauropods like the Brontosaurus - a long-necked herbivore who walked on four legs and was ten times its size.

One of the most striking features of skeleton was its long neck - and scientists now believe it to be the oldest long-necked dinosaur ever discovered

But unlike these giant beasts, Macrocollum itaquii walked on two legs when it roamed South America.

This discovery is particularly remarkable as experts believe it proved the dinosaurs chose to live in groups rather than alone.

'There are three articulated skeletons in five tons of rock,' Rodrigo Müller from the Federal University of Santa Maria in Brazil, told the Independent.

'This is unique. It suggests these animals probably died together, as they share the same degree of disarticulation. 

Two of the skeletons had perfectly preserved skulls (pictured) which is extremely rare in bones this old

'So if they died together, these dinosaurs probably lived together.'

The dinosaur skeletons were unearthed after Mr Müller's uncle found a group of fossils on a rural property in Agudo, southern Brazil in 2012.

This tip led to the discovery of the three skeletons, two of which had perfectly preserved skulls.