New tyrannosaur species 'found within duelling dinosaurs fossil'

The fossilised remains of two dinosaurs locked in combat have unleashed a fresh drama, suggesting diminutive specimens thought to be teenagers of Tyrannosaurus rex could instead belong to separate species.

- Nicola Davis Science correspondent

The “duelling dinosaurs” fossil, which reveals a triceratops in battle with a medium-sized tyrannosaur, was unearthed in Montana by commercial fossil hunters in 2006, and dates to shortly before the asteroid strike that ended the reign of the dinosaurs 66m years ago.

However it only became available for scientific research after it was acquired by the North Carolina Museum of Natural Sciences (NCMNS) in recent years.

Now researchers say a detailed analysis of the tyrannosaur reveals it is not simply a juvenile T rex, as many have thought, but an adult of a different species, Nanotyrannus lancensis.