NEW YORK (AP) — 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 ...

For decades, scientists believed that Tyrannosaurus rex reached its full size by the age of 25. However, new research has revealed that the iconic dinosaur likely required more time to reach its ...

Tyrannosaurus rex may have taken far longer to grow up than scientists once thought. By analyzing growth rings in fossilized leg bones from 17 tyrannosaur specimens and using new statistical methods, ...

Add Yahoo as a preferred source to see more of our stories on Google. This image shows an artist's illustration of the newly discovered dinosaur Joaquinraptor casali with an ancient crocodile relative ...

Turns out the key to discovering a new type of dinosaur might be a weird toe in an Idaho museum. Or a skull in Switzerland. Idaho State University paleontologists are examining whether these and other ...

Until now, estimating how old a dinosaur was when it died has been a fairly simple process — just count up the growth rings in its fossilized bones. "We always thought that those rings were formed ...