At academic conferences and inside the pages of scientific journals, palaeontologists have long argued about the features of the iconic Tyrannosaurus rex .

But a new study, published today in Nature , has the potential to finally put their argument to rest.

Historically, most dinosaur experts believed there was only one species of tyrannosaur roaming around North America between 69 – 66 million years ago in the late Cretaceous period.

Then in the 1940s, palaeontologists dug up a small skull that appeared come from a juvenile T. rex .

In the years since, there has been debate over whether the small dinosaur was actually a T. rex or another type of dinosaur completely.

Now, a new analysis of a controversial fossil known as "Duelling Dinosaurs" suggests the small tyrannosaur belo

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