A new fossil shows a prehistoric badger-like mammal and a dinosaur locked in 'mortal combat'

• A new fossil shows a badger-like mammal biting into a dinosaur. 
• The mammal was significantly smaller than the dinosaur and may have hunted in packs or solo.
• Researchers thought dinosaurs attacked mammals, but this fossil suggests the reverse is true, too.

An ancient, badger-like animal had no fear taking down a larger dinosaur.

A new paper in Scientific Reports describes a fossil of the cat-sized mammal, Repenomamus robustus, locked in "mortal combat" with a Psittacosaurus that was three times as large. The Repenomamus was between 6 and 8 pounds and appears to be biting into the dinosaur.