Anchiornis
Anchiornis is notable for its long forelimbs, which were 80% of the total length of the hind limbs. This is similar to Archaeopteryx; long forelimbs are necessary for flight. Anchiornis also had a more avian wrist than other non-avialan theropods. The authors first thought that Anchiornis could fly or glide. However, further finds showed that the wings of Anchiornis, while well-developed, were short when compared to later species like Microraptor, with relatively short primary feathers that had rounded, symmetrical tips, unlike the pointed, aerodynamically proportioned feathers of Microraptor. So the animal could glide, but probably not fly.