For a century scientists thought dinosaurs originated from South America some 220 million years ago.
However, a latest research has made an important discovery which could rock the dinosaur world.
A team of experts believe the dinosaurs originated in the Northern Hemisphere in an area now known as Britain.
They suggest that what we know about the evolution of dinosaurs, and where they first came from, might be wrong.
By looking at fossils they think that some of the first dinosaurs might have been around nearly 15 million years earlier that we thought.
The reassessment shows that the Tyrannosaurus Rex and Velociraptor have been wrongly placed.
Taking a deeper look at fossils, evidence suggests theropods like the T Rex should be moved to an entirely new branch that has northern origins.
To try and put it in simple terms: Dinosaurs are split into two groups. One group has bird-like hips and is called Ornithischia; and the other has reptile-like hips called Saurischia.
Theropods, which include the T Rex, were considered an offshoot from the Saurischia. But the new study has now moved them to the Ornithischia.