April 2, 2023

A Unique Discovery: Researchers Have Uncovered an Ultra-Rare Piece of Evidence That Dinosaurs Ate Mammals

A Unique Discovery: Researchers Have Uncovered An Ultra-Rare Piece Of Evidence That Dinosaurs Ate Mammals

A rendering of Microraptor zhaoianus. Credit: Ralph Attanasia III

New research on the preserved gut contents of Microraptor reveals a more varied diet than previously believed.

An international team of scientists discovered a rare piece of evidence suggesting that dinosaurs consumed mammals.

A recent study in the Journal of Vertebrate Paleontology details the discovery of a mouse-sized mammal foot inside the gut contents of a Microraptor zhaoianus, a small feathered dinosaur from the early Cretaceous period. This is a rare and unique find, as there is only one previous report of a dinosaur with mammalian gut contents, and it’s not closely related to Microraptor.

It’s extremely rare to find conclusive evidence of a dinosaur’s diet because of how difficult it is for a dinosaur’s gut contents to be preserved, says Corwin Sullivan, associate professor in the Department of Biological Sciences and co-author of the paper.

Mammal Foot in a Dinosaur - A Unique Discovery: Researchers Have Uncovered An Ultra-Rare Piece Of Evidence That Dinosaurs Ate Mammals

Mammal foot in a dinosaur. Credit: Alex Dececci

“There was always interest in [Microraptor’s] diet because there had been previous specimens that contained remains of different vertebrates inside the rib cage, but we have the first one that contains parts of a mammal,” he notes.

The Microraptor was found within Jurassic and Cretaceous lake deposits in what is now northeast China.

Previous Microraptor specimens from this area have been found with gut contents of a fish, bird, and lizard, indicating that these small dinosaurs had diverse diets. However, it remains unclear whether Microraptor consumed the contents in a predator-prey relationship or by scavenging. Researchers can only say conclusively that Microraptor was carnivorous.

Sullivan says information about dinosaurs’ diets is a key piece in the puzzle to learning more about what was going on at the time they roamed the Earth.

“We’re slowly gathering pieces of information about these past ecosystems and the animals that inhabited them. So what this discovery does is fill in a little bit of information in that it’s showing the diet of Microraptor was even broader, even more generalist, than we thought previously.”

“That tells us something about this animal and, by extension, tells us that there were generalist carnivores in these ancient ecosystems — that that niche existed.”

Reference: “Generalist diet of Microraptor zhaoianus included mammals” by David W. E. Hone, T. Alexander Dececchi, Corwin Sullivan, Xu Xing and Hans C. E. Larsson, 20 December 2022, Journal of Vertebrate Paleontology.
DOI: 10.1080/02724634.2022.2144337