Scientists recently discovered that the small dinosaur named Zheng Xiaoting Dragon is a relative of the ancestral birds, and the ancestors who lived in the late Jurassic period, very close to the relatives, by analyzing the shape of the birds, and similar birds, dinosaurs and early birds of the systematic development of the relationship  It is concluded that the ancestral bird is not a bird, but a primitive dinosaur claw dragon
The clawed dragon is a kind of bird that is closely related to the dinosaur
 So the ancestor bird is the ancestor of the dragon, not the ancestor of the bird