Bird display both clearly traditional reptilian characteristics: teeth, clawed fingers, and a long, lizard-like tail, as well as wings with flight feathers similar to those of modern birds. It is not considered a direct ancestor of birds, though it is possibly closely related to the true ancestor. The earliest known avialan fossils come from the Tiaojishan Formation of China, which has been dated to the late Jurassic period (Oxfordian stage), about 160 million years ago. The avialan species from this time period include "Anchiornis huxleyi", "Xiaotingia zhengi", and "Aurornis xui". The well-known early avialan, "Archaeopteryx", dates from slightly later Jurassic rocks
Dinosaur vision Dinosaur vision Dinosaur vision was, in general, better than the vision of most other reptiles, although vision varied between dinosaur species. Coelurosaurs, for example, had good stereoscopic or binocular vision, whereas large carnosaurs had poor binocular vision, comparable to that of modern alligators. Most carnosaurs, including "Carcharodontosaurus" and "Allosaurus", did not have very good binocular vision, comparable to modern alligators. They possessed binocular vision which was restricted to a region only 20° wide, which is understandable, as they hunted mostly large and slow prey. Their keenest sense was probably smell. Deinonychosaurs, like "Stenonychosaurus" and "Velociraptor", had better binocular vision than