For the longest time, what we imagined the world to be in the age of the dinosaurs was fairly set. The dinosaurs ruled, and mammals were tiny, cagey things. Rushing into shadows and underbrush to avoid hungry jaws. But newly discovered fossilized remains have thrown a bit of that hierarchy into question.
Unearthed in China’s Liaoning province, a 125 million-year-old fossil, shows a mammal and a dinosaur supposedly locked in battle with one another. The mammal, Repenomamus, roughly the size of a badger, is latched onto the side of parrot-beaked dinosaur, Psittacosaurus.
Jordan Mallon, author of the study of these fossils and paleobiologist at the Canadian Museum of Nature, is fascinated. This find changes how the food chain worked in the Cretaceous period. “Our best guess is that the mammal was in the middle of attacking the dinosaur,” Mallon said. Though some aren’t necessarily so sure. Elsa Panciroli, a researcher not involve in the study, feels there might be an alternate explanation. “The jury might be out a little bit for me as to whether the dinosaur had already died, maybe only just recently…or was in a very, very weakened state rather than it having been hunted down by this mammal.”
A Shift In Perspective
But Mallon’s research team has looked into that. If this were a scavenge on a dead dinosaur, there would be bite marks on other parts of the dinosaur’s bones. And the twisted-up semi-circle of the mammal seems to indicate violent action. “Mammals did occasionally prey on at least baby dinosaurs,” according to Mallon. “What’s new here is even a fully grown Psittacosaurus wasn’t necessarily safe from these smaller mammalian predators.”
We have our own records of modern mammals attacking creatures much larger than them. Desperate wolverines can manage to take down caribou. Even big cats will hunt larger prey if their usual fare is scarce. So if this Repenomamus was starving, we now have evidence that it was willing to go after a large meal. And this changes the perspective of the food chain landscape of the age of dinosaurs significantly. Perhaps mammals wouldn’t just hide away, but were opportunistic hunters willing to take on even larger prey in order to survive.
