Dinosaurs ‘too successful for their own good’

Dinosaurs spread across the world shows they may have been a victim of their own success, according to study.

UK researchers believe they were already in decline before the killer asteroid hit because they had occupied every habitat on Earth, according to BBC.

From their roots in South America, the dinosaurs migrated "in a frenzy of movement to cover the planet".

Hundreds of different dinosaurs appeared, from the ferocious T. rex to the gigantic long-necked Diplodocus.

But by the time the asteroid struck, killing them off, they were starting to decline, as they had ran out of space on Earth.

The theory, outlined in the journal, Nature Ecology and Evolution, reconstructs the paths taken by the dinosaurs as they moved out of South America.

"They burst on to the scene and really quickly moved to all parts of the Earth," said Dr Chris Venditti of the University of Reading, a co-researcher on the study.

The dinosaurs were able to take advantage of a "blank canvas" left by the extinction known as the Great Dying, just before they appeared, he said.

They quickly spread across the devastated planet, taking up every opportunity to expand, with little competition for food, space or resources from other animals.

But towards the end of their reign, their progress slowed, as they became adapted to almost every habitat on Earth. Only avian dinosaurs survived to become the birds we know today.