The discovery of remains belonging to a horse-sized ancestor of T-Rex are revealing how the dinosaur became one of Earth’s best ever predators.
The remains – unearthed in Uzbekistan – provide insights into how a family of small dinosaurs evolved over millions of years to become the ferocious giants, reports the Telegraph.
The study – published in Proceedings of the National Academy of Sciences – shows that the tyrannosaurs grew rapidly towards the end of the age of dinosaurs.
It has also revealed that their keen senses evolved earlier in much smaller species, allowing them to reach the top of the food chain.
Until now, little has been known about how tyrannosaurs became the giant, intelligent predators that dominated the landscape about 66 million years ago.
Scientists say this new species – Timurlengia euotica – lived around 90 million years ago and the remains fill a 20-million-year gap in the fossil record of tyrannosaurs.
It was roughly the size of a horse, weighed up to 250kg, had sharp teeth, and was a fast runner.
However, most interestingly, Timurlengia’s skull reveals its brain and senses were already highly developed.
It was around 100 million years later that tyrannosaurs had evolved into animals like T-Rex – which could weigh more than seven tonnes.
Dr Steve Brusatte, of the University of Edinburgh’s School of GeoSciences, who led the study, said:
Only after these ancestral tyrannosaurs evolved their clever brains and sharp senses did they grow into the colossal sizes of T. Rex.
Tyrannosaurs had to get smart before they got big.
Professor Hans Sues, of the museum said:
Timurlengia was a nimble pursuit hunter with slender, blade-like teeth suitable for slicing through meat.
It probably preyed on the various large plant-eaters, especially early duck-billed dinosaurs, which shared its world.