The ultimate attack. A badger-sized mammal was sinking its fangs into the ribs of a dinosaur three times its size when the two were frozen in ash from a volcanic eruption 125 million years ago. The wrestling scene, in a very well-preserved fossil discovered in China, suggests that small mammals could prey on the dinosaurs that dominated the fauna of the Cretaceous period, explain researchers in the journal Scientific Reports published on Tuesday.
This is the first time that a fossil has been discovered showing the fight between a mammal and a dinosaur, according to Jordan Mallon, paleontologist at the Canadian Museum of Nature, who co-authored the study led by Chinese scientists. Upon discovering the fossil, “I couldn’t believe my eyes,” he told AFP. Mammals were previously considered too small to attack dinosaurs during the few tens of millions of years they lived together.
The mammal cornered by its victim
But the fossil shows a Repenomamus robustus dominating a Psittacosaurus lujiatunensis, a four-foot-tall herbivore with a parrot-like beak. You can clearly make out the mammal – one of the largest of its time but weighing only a third of the dinosaur – which has sunk its sharp fangs into the ribs of its prey while clutching its hind leg.
The way the two skeletons are intertwined shows that the mammal was not feeding on the corpse of a dinosaur, according to Jordan Mallon. “The dinosaur collapsed and stuck a hind leg of the mammal in the hollow of its knees”, which suggests an attack by the mammal, notes the paleontologist. The skeleton of the dinosaur bears no other bite marks, which would be typical of those left by an animal that has devoured carrion.
A discovery from 2012
The two skeletons, almost complete, were discovered in 2012 in Liaoning, a province in northeastern China. The site, dubbed “Chinese Pompeii,” is home to numerous remains of dinosaurs and other animals preserved in volcanic debris similar to that of the ancient Roman city.
A first fossil discovered in 2005 suggested that mammals could feed on dinosaurs. It showed that a small Psittacosaurus had ended up in the stomach of a Repenomamus. But this new fossil is the first evidence that “there were at least a few fiery mammals around the Cretaceous […], capable of bringing down an adult dinosaur,” according to Jordan Mallon. The discovery will be exhibited in the museum of a primary school in the Chinese city of Weihai.