Everything scientists believed about the T-Rex could be wrong after a study proved the existence of its smaller cousin.

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

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

There are literally decades of research... based on a premise that this article overturns,” said one paleontologist.

An extremely rare pregnant Tyrannosaurus Rex dinosaur skeleton first found in Montana has gone on display, but Americans wanting to check it out for themselves might have quite a journey on their ...

A fossilized partial dinosaur skull originally thought to be from a Tyrannosaurus rex might actually represent a previously unknown species, according to a paper published Thursday in the journal ...