This fossil of a mammal biting a dinosaur captures a death battle's final moments

When dinosaurs ruled the Earth, we tend to think of the mammals at the time — including our distant ancestors — as small and quivering in the shadows.

"We've always had this picture of mammals as the literal underdogs," says Elsa Panciroli, a paleontologist at the Oxford University Museum of Natural History. "They're being trampled. They're cowering in the darkness at night, just trying to avoid being eaten."

But a remarkable new, conjures a rather different possibility. It consists of two intertwined skeletons — an upstart mammal sinking its teeth into a much larger dinosaur.