Scientists have documented one of the rarest evidence of a dinosaur eating a mammal from a fossil specimen found in the ancient forests of what is now China.
The study, published Wednesday in the Journal of vertebrate Paleontology, describes a small, feathered dinosaur Microraptors preserved with the foot of a small mammal inside its rib cage.
Researchers, including David Hone of Queen Mary University of London, say the dinosaur lived during the Early Cretaceous about 120 million years ago in what is now China.
“This study paints a picture of a fascinating moment in time — of a dinosaur eating a mammal — even if it’s not as scary as anything in Jurassic Park,” said Dr. Hone.
The findings also fit with what is seen in other small dinosaurs whose stomach contents suggest they tended to eat a variety of other animals, particularly those that were smaller than themselves.
Scientists say the microraptor dinosaur was the size of a crow with long feathers on its arms and legs, probably gliding from tree to tree and hunting small animals to eat.
While the dinosaur was first described in 2000, scientists say key details of another animal’s remains within it had been lost.
In the new study, researchers discovered the foot of an ancient mammal preserved between the ribs of the microraptor.
“It’s so rare to find examples of food inside dinosaurs, so each example is really important as it provides direct evidence of what they were eating,” Dr. Hone said in a statement.
“While this mammal absolutely would not have been a human ancestor, we can look back on some of our ancient relatives as meal for hungry dinosaurs,” he added.
The foot, found by scientists within the dinosaur’s remains, likely belonged to a very small mammal, about the size of a modern mouse, the researchers say.
Analysis of the foot bones suggests that the small mammal probably lived most of its life on land and was not a good climber.
Previous studies have documented Microraptors specimens containing a bird, lizard and fish, and with the new discovery of these dinosaurs also eating mammals, researchers say prehistoric reptiles had a different diet and weren’t specialists.
However, it’s not clear whether the dinosaur directly preyed on the mammal or ate the small animal.
“The nice thing is, like your pet cat who was roughly the same size, Microraptors it would have been an easy animal to live with but a terror if it got out because it would hunt anything from birds in your feeder to mice in your hedge or fish in your pond,” Alex Dececchi, another author of the Mount Marty study College, he said.
“So we have it, dinosaurs — perhaps unsurprisingly — ate mammals at least occasionally,” the researchers wrote in a blog post.