Ornithurae Ornithurae Ornithurae (meaning "bird tails" in Greek) is a natural group which includes the common ancestor of "Ichthyornis", "Hesperornis", and all modern birds as well as all other descendants of that common ancestor. Ernst Haeckel coined the name in 1866 and included in the group all "true birds" with the "characteristic tail morphology of all extant birds" (translation by Jacques Gauthier). This distinguishes the group from "Archaeopteryx", which Haeckel placed in another new group called Sauriurae. Said simply, modern birds have short, fused pygostyle tails, while "Archaeopteryx" retained the long tail characteristic of non-avian theropod dinosaurs. Gauthier converted Ornithurae into
Dinosaur vision had eyes on the sides of the head, so they could quickly spot approaching predators. They also had depth perception. 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