Debate kicked off in 1988 when a single small tyrannosaur skull discovered four decades earlier was given its own species name: Nanotyrannus lancensis. It carried some features which differed from T.

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

“The fossil, part of the legendary ‘Dueling Dinosaurs’ specimen unearthed in Montana, contains two dinosaurs locked in prehistoric combat: a Triceratops and a small-bodied tyrannosaur. That ...