Determining what dinosaurs ate is normally a process of informed guesswork, but not for one lucky team of researchers. Rather than having to rely on analysing teeth or looking for bite marks, they could simply look at the inside of their fossil.
In a new paper, Jingmai O’Connor, of the Chinese Academy of Sciences in Beijing, and her team report a nicely preserved raptor that has its last meal equally well preserved inside it.
“Stomach contents, although considerably rarer than indirect inferences from bite marks, coprolites [fossilised dung], and other trace indicators—are the only certain ways to infer fossil diets,” they write in PNAS, “in this case, little doubt can remain about the identity of the predator and its prey.”
The predator in question is Microraptor gui, a small dinosaur from the early Cretaceous that sported four feathered limbs resembling wings. Inside the microraptor are the remains of a bird.
As the bird is still articulated the researchers suggest it was probably captured and eaten, rather than scavenged. Additionally, the bird is of a kind thought to have dwelled in trees, meaning that the microraptor probably hunted up there too.
There has been debate over exactly what M. gui did with its four feathered limbs and what this might mean about the evolution of flight (see, for example, Distorted Microraptor specimen is not ideal for understanding the origin of avian flight). But, O’Connor et al note, we can now say that it fed on arboreal birds and “was spending a substantial amount of time in the trees”.