Scientists thought this fossil was a teen T. rex. Turns out it's a new tyrannosaur

In this illustration, a pack of Nanotyrannus attacks a juvenile T. rex. Scientists say a well-known fossil shows that there was more than one tyrannosaur species roaming the Earth.

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

(Image credit: Anthony Hutchings)