A mammal was sinking its teeth into the ribs of a dinosaur three times its size. Suddenly, they were buried in volcanic ash, turning their deadly fight into stone! It happened 125 million years ago.
The fight scene, preserved in a fossil found in China, tells us that small mammals preyed on the dinosaurs that ruled Earth during the Cretaceous period.
Jordan Mallon, a palaeontologist at the Canadian Museum of Nature, says that when he first saw the fossil: "My eyes popped out of my head!"
He thinks the fossil is the first ever found that shows a mammal and dinosaur fighting each other. Before now, mammals were thought to be too small to prey on the dinosaurs that ruled the world for millions of years.
But the fossil shows a badger-sized mammal sitting on top of a plant-eating dinosaur that was 120cm tall and had a beak like a parrot.
The mammal – one third the weight of the dinosaur – is sinking his sharp teeth into the dinosaur's ribs and gripping onto its leg.
The way the pair are intertwined shows that the mammal was not scavenging on a dead dinosaur, Jordan says. "The dinosaur has fallen down and trapped the back leg of the mammal in the fold of its knee," showing it was an attack, he says.
It is rare for mammals to prey on animals so much larger than them, but one example today is how wolverines have been seen hunting far-larger reindeer.
It was not possible to tell from the fossil if the mammal hunted alone or in a pack.
The fossil skeletons were found in Liaoning province in 2012. They were found at a place nicknamed "Chinese Pompeii" because of how many dinosaurs have been found preserved by volcanic ash there, similar to the ancient Roman city Pompeii. The "once-in-a-lifetime" fossil is being exhibited at a school in Weihai.
Five things to know about mammals
1. A mammal is an animal that breathes air, has a backbone, and grows hair at some time during its life. Also, all female mammals have glands that can produce milk.
2. Mammals are among the most intelligent of all living creatures.
3. Mammals include a wide variety of animals, from cats to humans to squirrels to whales. There are more than 5,000 species of living mammal.
4. Most mammals live on land: on the ground, in trees or underground. Some mammals, like otters, beavers and seals, live on land and in water. Whales and dolphins are mammals that spend their whole life in water.
5. The Philippine bamboo bat weighs only 1.5 grams, but the blue whale can weigh 180,000 kilograms!
