Piscivory in the feathered dinosaur 'Microraptor'

The largest specimen of the four-winged dromaeosaurid dinosaur 'Microraptor gui' includes preserved gut contents. Previous reports of gut contents and considerations of functional morphology have indicated that 'Microraptor' hunted in an arboreal environment. The new specimen demonstrates that this was not strictly the case, and offers unique insights into the ecology of nonavian dinosaurs early in the evolution of flight. The preserved gut contents are composed of teleost fish remains. Several morphological adaptations of 'Microraptor' are identified as consistent with a partially piscivorous diet, including dentition with reduced serrations and forward projecting teeth on the anterior of the dentary. The feeding habits of 'Microraptor' can now be understood better than that of any other carnivorous nonavian dinosaur, and 'Microraptor' appears to have been an opportunistic and generalist feeder, able to exploit the most common prey in both the arboreal and aquatic microhabitats of the Early Cretaceous Jehol ecosystem.