The first dinosaurs emerged in Laurasia, present-day United Kingdom, in the northern hemisphere 245 million years ago, a group of scientists suggested on Wednesday. The new theory aims to revamp the family tree of the animals, who the scientists so far believed came into existence 230 million years in Gondwana in the southern hemisphere. It also challenges the clubbing together of the meat-eating group of dinosaurs, known as theropods, with the long-necked plant-eaters. The meat-eaters include the tyrannosaurus-rex or T-rex.

The research, published in the journal Nature, proposes a re-look at the dinosaur family tree put together by Harry Govier Seeley of King’s College London in 1888. The paper says that 75 species of the animal may have come from the Northern Hemisphere, specifically modern day Scotland, reported The Guardian. It also suggests that the animals may have come into existence 15 million years before what has been believed so far.

“The northern continents certainly played a much bigger role in dinosaur evolution than we previously thought and dinosaurs may have originated in the UK,” lead author Matthew Baron of Cambridge University told BBC. “This is obviously going to be met with some hostility from Southern American researchers.”

Till now, dinosaurs have been divided into two groups – Ornithischia those with hip structure resembling that of birds; and Saurischia, those with lizard-like hips. According to this classification, the T.rex belonged to the Saurischia group. However, the new research paper has found that the T-rex has more in common with the Ornithischia group than believed so far. The proposed family tree has T-rex in a new category – Ornithoscelida. The scientists said the Stegosaurus-like dinosaurs and T-rex have similar anatomical structure such as skull, hind limbs and ankle bones and should be put in the same group.