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 CretaceousThe Cretaceous is a geological period that lasted from about 145 to 66 million years ago. It is the third and final period of the Mesozoic Era. It ended with the Cretaceous–Paleogene extinction event.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>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. Credit: Alex Dececci
“There was always interest in [Microraptor’s] diet because there had been previous specimens that contained remains of different vertebratesVertebrates are animals that have a backbone and include mammals, birds, reptiles, amphibians, and fish. They have a more advanced nervous system than invertebrates, allowing them greater control over their movements and behaviors, and they are able to move and support their body weight using their spine. Vertebrates are found in many habitats and play important roles in the ecosystem as predators, prey, and scavengers.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>vertebrates inside the rib cage, but we have the first one that contains parts of a mammal,” he notes.
The Microraptor was found within JurassicThe Jurassic period is a geologic time period and system that spanned 56 million years from the end of the Triassic Period about 201.3 million years ago to the beginning of the Cretaceous Period 145 million years ago. It constitutes the middle period of the Mesozoic Era and is divided into three epochs: Early, Middle, and Late. The name "Jurassic" was given to the period by geologists in the early 19th century based on the rock formations found in the Jura Mountains, which were formed during the Jurassic period.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>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
Source: SciTechDaily
