A new study reveals Tyrannosaurus rex took 40 years to reach full size, not 30, as previously thought. Researchers analyzed ...

WASHINGTON (Reuters) - Surmising even the physical appearance of a dinosaur - or any extinct animal - based on its fossils is a tricky proposition, with so many uncertainties involved. Assessing a ...

For decades, scientists have been counting annual growth rings—similar to tree rings—inside fossilized leg bones of Tyrannosaurus rex to estimate how old the giant carnivores were when they died and ...

A new dinosaur species may be the closest known relative of Tyrannosaurus rex, a new study suggests. The research reshapes scientists’ understanding of how the most famous dinosaur – T. rex – might ...

Billions of Tyrannosaurus rex roamed North America during their fascinating reign as top predators, according to a team of researchers that went about the daunting task of making the calculation.

Pioneering techniques used in this research may soon be applied to other dinosaur fossils and alter the course of ...

It's known as the "Dueling Dinosaurs" fossil: A triceratops and a tyrannosaur, skeletons entangled, locked in apparent combat right up until the moment of their mutual demise. Even in the Hell Creek ...

Scientists have long puzzled over the origins of a mysterious dinosaur excavated in the 1940s: Was it a young T. rex or another type of dinosaur? At first, researchers had only a tyrannosaur skull to ...