An “unusual” fossil revealed that a small, carnivorous dinosaur consumed mammals, demystifying the diet of the long-extinct creature, researchers said.
An intact mammal foot was spotted inside the rib cage of a fossilized Microraptor zhaoianus, a feathered dinosaur, according to a study published in the Journal of Vertebrate Paleontology and an accompanying news release.
“At first, I couldn’t believe it. There was a tiny rodent-like mammal foot about a centimeter long perfectly preserved inside a Microraptor skeleton,” Hans Larsson, McGill University professor and co-author of the study, wrote in the release. “These finds are the only solid evidence we have about the food consumption of these long extinct animals – and they are exceptionally rare.”
Larsson made the discovery while perusing a Chinese museum’s collection.
There are only 20 other documented cases of discernible food being found inside carnivorous dinosaur skeletons, researchers said.
The Microraptor, one of the smallest known dinosaur species, had wings on all four limbs and was only about the size of a crow, according to researchers. It was first discovered in northern China about 20 years ago.
The creature, which roamed the Earth about 125 million years ago, only weighed about 2 pounds and may have been capable of flying, according to the Natural History Museum in the U.K.
The new find suggests that the feathered creature was not a picky eater, researchers said.
“Knowing that Microraptor was a generalist carnivore puts a new perspective on how ancient ecosystems may have worked and a possible insight into the success of these small, feathered dinosaurs,” Larsson stated.
Generalist carnivores help stabilize ecosystems because they prey on multiple species that might have different population sizes at different times, researchers said.
“This study paints a picture of a fascinating moment in time — one of the first record(s) of a dinosaur eating a mammal — even if it isn’t quite as frightening as anything in Jurassic Park,” David Hone, one of the study’s co-authors, wrote in a Queen Mary University of London news release.