A new smaller breed of the world's best known dinosaur is thought to have once roamed the Arctic.
Dating back 70 million years, this new pygmy tyrannosaur is smaller but otherwise extremely similar to its larger sub-tropic counterpart. Palaeontologists had initially believed that a specimen unearthed in 2006 was simply a juvenile until further research later revealed that it was in fact a fully matured adult of a different species.
While the regular Tyrannosaurus rex can grow up to 40ft in length and weigh 4 tons, this new smaller species, known as Nanuqsaurus hoglundi, measures only 25ft and weighs 1,000lbs.
"The 'pygmy tyrannosaur' alone is really cool because it tells us something about what the environment was like in the ancient Arctic," said study co-author Anthony Fiorillo.
"But what makes this discovery even more exciting is that Nanuqsaurus hoglundi also tells us about the biological richness of the ancient polar world during a time when the Earth was very warm compared to today."