June 4 (Reuters) - A rare fossil of an adolescent Tyrannosaurus rex has been excavated in North Dakota's badlands - a find noteworthy for the scientific insight it may offer into the life history of ...

Tyrannosaurus rex may have been a much slower grower than scientists realized. A new study of 17 tyrannosaur fossils found that the giant predator likely took about 40 years to reach its full size of ...

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 ...