Four-winged dinosaur: Scientists just found a four-winged dinosaur in northwestern China, and it may be the predator that left behind piles of crushed bird bones

Paleontologists working in northwestern China had been stuck for years on a strange puzzle. According to a new study, ‘First Non-Avian Theropod (Dromaeosauridae, Microraptorinae) from the Bird-Bearing Lower Cretaceous Xiagou Formation of the Changma Basin, Gansu Province, Northwestern China,’ published in the Annals of Carnegie Museum by Zhou et al. , a fossil site in the Changma Basin has produced the remains of more than 100 prehistoric birds.

But among those remains were clusters of broken bones crushed into pellets, similar to those coughed up by modern owls. The scene was eerily familiar: modern owls, after a meal, make nearly identical pellets, regurgitating the bones of their prey in compressed bundles. Something at Changma had been doing the same thing 124 to 120 million years ago. The trouble was, nobody could find the predator.