A fossil of a dinosaur that was thought to feed on tree-living animals has been found with a fish in its belly.

Credit: L. FANG

Used to understand the origins of flight, fossils of the four-winged feathered raptor Microraptor gui, which lived 120 million years ago have previously been found with a bird and a potentially tree-climbing mammal preserved in their guts.

Scott Persons at the University of Alberta in Edmonton, Canada, and his colleagues report on a fossil (pictured) containing a partially digested fish. The authors also describe adaptations — such as front teeth that project forward — that are similar to those seen in fish-hunting animals.

The feeding habits of Microraptor spp are now the best sampled of any non-avian dinosaur, revealing it as a generalist predator in arboreal and aquatic habitats, the authors say.

Evolution http://dx.doi.org/10.1111/evo.12119 (2013)