Unusual prehistoric find: Mammal attacks dinosaur

An unusual scene that opens up a new vein of exploration for paleontologists and scientists are fossils found in China, where they found a badger-like mammal in the midst of a deadly fight with the dinosaur Psittacosaurus lujiatunensis more than 125 million years ago.

“The two animals are locked in a deadly fight, closely intertwined, and this is one of the first evidence of true mammalian predatory behavior towards a dinosaur,” explains Dr. Jordan Mallon, a paleobiologist at the Canadian Museum of Nature and co-author of the study. study published today in the journal Scientific reports.

The presence of the fossil casts doubt on the notion that dinosaurs faced little threat from their mammalian contemporaries during the Cretaceous, when dinosaurs were the dominant animals. The rare fossil is now in the collection of the Weihai Ziguang Shi Yan School Museum in China’s Shandong province.

The herbivorous psittacosaurus are among the earliest known dinosaurs and lived in Asia during the early Cretaceous period, approximately 125 to 105 million years ago. The mammal in the fossil pair is a badger-like animal called Repenomamus robutus.

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

The fossil was found in the Chinese province of Liaoning in 2012, and both skeletons are nearly intact. Their integrity stems from the fact that they come from an area known as the Liujitun fossil beds, which have been nicknamed the “Chinese Dinosaurs of Pompeii”.

The name refers to the many fossils of dinosaurs, small mammals, lizards and amphibians in the area, animals that were suddenly en masse buried under landslides and debris after one or more volcanic eruptions. The existence of volcanic material in the rocky matrix of the studied fossil was confirmed after analysis by Canadian Museum of Nature mineralogist Dr. Aaron Lussier.

A detailed study of the fossil pair shows that psittacosaurus it lies face down, its hind limbs bent on either side of the body. body repenomamus twists to the right and mounts its prey along with the mammal grasping the jaw of the largest dinosaur. The mammal also bites into some of the ribs and hind leg repenomamus grabs the dinosaur’s hind leg. “The body of evidence suggests that there was an active attack,” says Dr. Mallon.

Mallon, Wu and their colleagues ruled out the possibility that the mammal was simply looking for a dead dinosaur. For example, there are no teeth marks on the bones of the dinosaur, which suggests that it did not collect garbage, but rather hunted it. And it’s unlikely that the two animals would have been so entangled if the dinosaur had been dead before the mammal found it. Position repenomamus about him psittacosaurus suggests that he was also the attacker.

“It may be a case of what is represented in the fossil, with repenomamus eat in psittacosaurus while he was still alive before they were both killed afterwards,” Mallon explains.