After decades of fierce debate, researchers say fossils once thought to be juvenile T. rex actually belong to a separate, ...

An argument over whether fossils from several small dinosaurs represent a juvenile Tyrannosaurus rex or smaller adults of a ...

Paleontologists have long debated whether small tyrannosaurs were their own species or simply teenage T. rexes. This debate ...

At the twilight of the age of dinosaurs, an agile and vicious predator named Nanotyrannus prowled western North America, ...

For more than three decades, paleontologists have argued over whether a lithe predatory dinosaur called Nanotyrannus ever ...

For decades, paleontologists debated whether fossils were of a young T. rex or a species called nanotyrannus. A new study ...

Specifically, whether or not certain fossils found in Montana belonged to a young Tyrannosaurus rex or a completely separate, ...

A new look at the "Dueling Dinosaurs" fossil reveals that Tyrannosaurus rex was not the only tyrannosaur roaming the land.