A labrador-sized dinosaur was wrongly categorised when it was found and is actually a new species, scientists have discovered.
Its new name is Enigmacursor - meaning puzzling runner - and it lived about 150 million years ago, running around the feet of famous giants like the Stegosaurus.
It was originally classified as a Nanosaurus but scientists now conclude it is a different animal.
On Thursday it will become the first new dinosaur to go on display at the Natural History Museum (NHM) in London since 2014.
BBC News went behind the scenes to see the dinosaur before it will be revealed to the public.
