Tianyulong confuciusi was a revolution in dinosaur paleontology. This heterodontosaurid dinosaurus was the first non-theropod dinosaur with evidence of feather-like structures.
This implies that the appearance of feathers may have occurred in a common ancestor of ornithischians and saurischians, so possess feathers is a primitive character and not a derived one. This opens a wide scene in wich many dinosaurs, of different group may have feathers, at least in one stage of their growth. Later discoveries have shown this to be a correct hypotesis.