China-Canada joint fossil discovery reveals dinosaur fight from 125 million years ago

An extraordinary story has emerged with the recent discovery of rare fossils dating back approximately 125 million years, through joint efforts between Chinese and Canadian researchers. These fossils unveil a remarkable encounter where a large herbivorous dinosaur fell victim to an attack by a carnivorous mammal.

About the size of a large dog, the dinosaur fossil was identified as Psittacosaurus whereas the badger-like mammal fossil is an example of Repenomamus robustus, one of the largest mammals during the Cretaceous - a time when mammals had not yet become the dominant animals on Earth.

The two were found "locked in mortal combat," and "intimately intertwined," said Dr Jordan Mallon, the palaeobiologist with the Canadian Museum of Nature who handled the fossils.

The discovery of these two species Psittacosaurus and Repenomamus robustus was not a "novel finding" in and of itself, but the "predatory behaviour" on display is a rare find, Mallon emphasized.

Wu Xiaochun, a core figure on the project, told the Global Times that the fossils reveal the mammal was not feasting on an already dead dinosaur, but was actively attacking the animal.

"Similar articles that feature a predator mammal have been published before, but only until this one can we show it had its prey alive," said Wu, who is also the head of the Paleobiology Research and Collections Department of the Canadian Museum of Nature.

A typical case of a smaller predator attacking bigger prey, the fossils show, according to Mallon, that they had both lost their lives in the "roily aftermath."

While the fossil had been researched for years since it was first excavated in 2012 in Northeast China's Liaoning Province, the study was only published on Tuesday in Scientific Reports, a scholarly journal. Mallon is the co-author of the paper.

From excavation to publication, Wu played a pivotal role in bringing the researchers from China and Canada together for the project.

In 2012, the fossil was collected in Northeast China's Liaoning Province, more exactly from the Liujitun fossil beds, which are dubbed "China's Dinosaur Pompeii." After excavation, the fossils were in the care of study co-author Dr Han Gang in China, and later Wu helped Han connect with Mallon.

The research projects between China and Canada "will continue in 2023," Wu revealed to the Global Times.

"Joint research projects such as one on a marine reptile in Southwest China's Guizhou Province, is coming along," Wu said.