I have described two specimens of Microraptor preserving ingested remains. One preserves the articulated remains of an enantiornithine bird; the other preserves the articulated remains of previously unknown species of lizard (named Indrasaurus wangi).
These specimens together indicate that Microraptor was an agile, opportunistic predator that swallowed prey largely whole and head first, similar to most extant carnivorous birds and lizards.
Preserved indicators of diet are extremely rare in the fossil record; even more so is unequivocal direct evidence for predator–prey relationships. Here, we report on a unique specimen of the small nonavian theropod Microraptor gui from the Early Cretaceous Jehol biota, China, which has the remains of an adult enantiornithine bird preserved in its abdomen, most likely not scavenged, but captured and consumed by the dinosaur. We provide direct evidence for the dietary preferences of Microraptor and a nonavian dinosaur feeding on a bird. Further, because Jehol enantiornithines were distinctly arboreal, in contrast to their cursorial ornithurine counterparts, this fossil suggests that Microraptor hunted in trees thereby supporting inferences that this taxon was also an arborealist, and provides further support for the arboreality of basal dromaeosaurids.
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