Scientists in the UK have just made a huge discovery about dinosaurs, a finding so big that it could permanently alter our understanding of how they came about, and even how they evolved. The study claims that rather than originating in the Southern Hemisphere, as had been widely believed, the first dinosaurs may have been in Scotland.

Dinosaurs may have evolved from the Saltopus, a small animal that lived eons ago in Scotland, according to the study, which was published in the journal Nature. It’s a big finding because, if true, it would totally upend the dinosaur family tree, and it would also suggest that dinosaurs first appeared on the Earth 15 million years earlier than had been thought.

It was inconsistencies in the bone structures of early dinosaurs compared to how they would be if the current evolutionary family tree was correct that tipped off scientists.

“When we started our analysis, we puzzled as to why some ancient ornithischians appeared anatomically similar to theropods,” Lead author, Matthew Baron, said in a statement from the University of Cambridge. “Our fresh study suggested that these two groups were indeed part of the same clade. This conclusion came as quite a shock since it ran counter to everything we’d learned.

“The carnivorous theropods were more closely related to the herbivorous ornithischians and, what’s more, some animals, such as Diplodocus, would fall outside the traditional grouping that we called dinosaurs. This meant we would have to change the definition of the ‘dinosaur’ to make sure that, in the future, Diplodocus and its near relatives could still be classed as dinosaurs.”