Fossil shows mammal and dinosaur ‘engaged in deadly combat’

A unique fossil of a mammal and a dinosaur from about 125 million years ago that “were engaged in a mortal battle” challenges the notion that dinosaurs ruled the land, researchers wrote in a study published Tuesday.

The new fossil, discovered on May 16, 2012 in China’s Liaoning province, shows a mammal attacking a dinosaur about three times its size. The mammal, a carnivorous Repenomamus robustus, was the clear attacker, researchers wrote in the journal Scientific Reports.

“The mammal died when it bit two of the dinosaur’s left front dorsal ribs; its lower jaw dips down into the hardened sediment to grip the bones tightly,” the study authors write.

The discovery of the two creatures is among the first evidence demonstrating actual predation by a mammal over a dinosaur, said Dr. Jordan Mallon, paleobiologist at the Canadian Museum of Nature and co-author of the study, in a press release.

Repenomamus robustus is a badger-like animal that was one of the largest Cretaceous mammals.

The dinosaur has been identified as a Psittacosaurus, a herbivore the size of a large dog.

Paleontologists had previously suspected that Repenomamus hunted dinosaurs because fossilized bones were found in the mammal’s stomach.

“The coexistence of these two animals is not new, but what is new to science about this amazing fossil is the predatory behavior it exhibits,” Mallon said.

Experts believe the attack sustained when the two animals got caught in a volcanic flow. The area where the fossil was discovered is known as “China’s Pompeii” due to the many fossils of animals buried en masse by mudslides and debris after one or more volcanic eruptions.

After the find, scientists worked to confirm that the fossil was not a fake. The researchers said the intertwined skeletons and the completeness of the skeletons suggest the find was legitimate and the animals were not transported before burial.

Steve Brusatte, a University of Edinburgh paleontologist who was not involved with the research, tweeted about the find and suggested it was as if Wile E. Coyote had caught the roadrunner. He said the find “turns the ancient history of dinosaur dominance on its head.”