Tyrannosaurus Rex was probably an invasive species from Asia that moved into western North America, according to a Scottish-based paleontologist. Jim Drury reports.
It was the king of the dinosaurs, dominating what's now known as western North America, at the end of the Cretaceous Period. But palaentologists Steve Brusatte and Thomas Carr say T Rex wasn't originally an American native. SOUNDBITE (English) STEPHEN BRUSATTE, PALAEONTOLOGIST, UNIVERSITY OF EDINBURGH, SAYING: "It looks like T-Rex was an Asian immigrant to North America. It was an invasive species that came in right at the end of the time of dinosaurs, it came from Asia, and when it came from Asia it swept across North America and very quickly it was living everywhere in western North America." The pair have put together a family tree of the Tyrannosauroids after analysing 28 different species. Tyrannosaurs' ancestors lived on the supercontinent Pangaea, which began to break apart about 200 million years ago. The seaway between Asia and North America disappeared 67 million years ago, leaving a land bridge between the two continents. The pair think T Rex may have used this route into North America. Their research suggests the early Tyrannosauroids were very small. SOUNDBITE (English) STEPHEN BRUSATTE, PALAEONTOLOGIST, UNIVERSITY OF EDINBURGH, SAYING: "The family tree tells us you had all these species of small Tyrannosaurs that were just about our size, maybe a little bit bigger - up to about the size of a horse - but nothing like a T-Rex and it was only those enormous, colossal, apex predator, bone-crunching T-Rex type Tyrannosaurs that came in right at the end of the dinosaurs just about 80 million years ago." Their research was published in online, open access, journal Scientific Reports.