The current theory of dinosaurs may be wrong. A review of thousands of fossils and a new theory about dinosaurs were announced on Wednesday. The new study was published in the journal Nature.

One of the implications is that dinosaurs first emerged 15 million years earlier than what was previously believed. Researchers found fossil evidence that suggests their origin occurred further north of UK said Matthew Baron, lead author from Cambridge University.

The previous version of the dinosaur family tree was developed 130 years ago by paleontologist Harry Govier Seeley at Kings College, London. Seeley compared the size, shapes and arrangements of the fossilized bones of different dinosaur species. He was able concluded that there were two main groups of dinosaurs.

According to BBC the two groups were Ornithischia and Saurishcia. The Ornithischia group was dinosaurs whose hip bones were like those of modern-day birds while the Saurischia had reptile-like hip bones.

Ornithischia were all exclusively plant-eaters or herbivores such as the Stegosaurus and Triceratops. The Saurischia group had two branches, the herbivores, such as the Brontosaurus, and the meat-eaters or carnivores, such as the T-rex.

In the new hypothesis, researchers studied more bones and included more species that have been discovered only in the past 30 years. After completely reshaping the dinosaur family tree, their analysis suggested that Seeley's theory were wrong.

The new approach argued that the meat-eaters group to be moved into the same classification as the bird-hipped dinosaurs. They found that the T-rex is more closely related to the Ornithischia line than Saurischia.

Two crucial fossils were found in Scotland and England, a reason to believe that the Northern Hemisphere and the UK is more likely the place were the first dinosaurs emerged. The study also suggests that the first dinosaurs emerged 247 million years ago, which 10 million years earlier than the standard theory according to USA Today.

The researchers said it's difficult to make any firm claims at this stage for their origins. They hope that the study will spur paleontologists to search for more fossil evidence to back up the new ideas.