Newly Described Fossil Unveils Ancient Battle Between Mammal and Dinosaur
The work of a paleontologist is often compared to solving a puzzle with missing pieces. However, every once in a while, researchers are fortunate enough to stumble upon nearly complete skeletons that offer a glimpse into the behavior of ancient creatures. This appears to be the case with a newly described fossil of a badger-like mammal and a Labrador retriever-sized dinosaur locked in a fierce fight.
A team of Canadian and Chinese researchers published their findings in the journal Scientific Reports on Tuesday, along with a section dedicated to addressing concerns of the fossil’s authenticity. The prehistoric skirmish is believed to have taken place around 125 million years ago in what is now northeastern China. The fossil depicts combat between a mammal called Repenomamus robustus and a bipedal, plant-eating relative of Triceratops called Psittacosaurus lujiatunensis, challenging conventional wisdom about the behavior of mammals during that time period.
Although the dinosaur had a size advantage, Repenomamus, with its teeth clamped into Psittacosaurus’s rib cage, appears to have held its ground. The absence of scavenger marks on the dinosaur’s bones suggests that the encounter occurred while Psittacosaurus was still alive. Paleontologist Jordan Mallon, a co-author of the study, compares Repenomamus to small carnivorous mammals today that are capable of taking down much larger prey.
The successful preservation of the animals mid-battle required a combination of luck and unfortunate circumstances. A volcanic eruption unleashed ash, which could have turned into a mudslide due to seasonal flooding or heavy rains. In the midst of their fight, the mud flow caught Repenomamus and Psittacosaurus off guard, preserving them for 125 million years.
The fossil was unearthed in 2012 by farmers in China’s Liaoning province and acquired by Gang Han of Hainan Vocational University of Science and Technology, a co-author of the study. The researchers took precautions to ensure the fossil’s authenticity, given the prevalence of fossil forgeries. They examined the surrounding rock and found that the mammal’s lower jaw was genuinely biting into the dinosaur’s ribs. The composition of the rock in the fossil and the fossil beds matched, providing further evidence of its legitimacy.
David Grossnickle, an evolutionary biologist at the University of Washington who was not involved in the study, acknowledges the possibility of parts of the specimen being forged but believes the biting mammal skull is genuine and still an extraordinary find. The fossil provides tantalizing evidence of how mammals and dinosaurs interacted and offers valuable information about ancient ecosystems.
While the study does not definitively prove that Repenomamus hunted dinosaurs for food, it does contribute to the growing evidence of the diverse ecological roles of Mesozoic mammals. The findings challenge the traditional perception of meek mammals coexisting with dominant reptiles and suggest that they may have had their own means of survival and interaction with the environment.
Overall, this fossil discovery provides invaluable insights into the dynamics of ancient ecosystems and allows scientists to piece together the puzzle of our planet’s prehistoric past.