Massive T. rex skull unearthed in Montana

Professor Greg Wilson, of Washington University and the museum, said: “When we started to see those teeth with the skull, we knew we had a fantastic specimen.

“The combination of the skull features, the size of the bones, and the honeycomb-like appearance of the bones tell us this is a T rex. This was a very exciting moment for us.

“We think the Tufts-Love Rex is going to be an iconic specimen for the Burke Museum and the state of Washington and will be a must-see for dinosaur researchers as well.”

They believe it was aged about 15 to 25 when it died, possibly after falling into the river and drowning. It may also have died elsewhere and then been washed into the river by a flash flood.

The dinosaur would have stood about 15 to 20 feet (4.5m to 6m) at its hips and would have been more than 40ft (12m) in length, the museum said.

It is not yet known whether it was male or female but the researchers might be able to find this out if more bones are discovered.

It lived near the end of the Cretaceous period, when dinosaurs became extinct after a massive asteroid hit the Earth. A recent study concluded that it hit huge oil deposits in Mexico, sending thick black smoke all over the world, causing it to cool significantly and experience devastating droughts.