Confuciusornis is a genus of crow-sized, primitive, birds from the Early Cretaceous Yixian Formation (Jianshangou Beds) of China, dating to 124.6 million years ago. Like modern birds, Confuciusornis had a toothless beak, but close relatives of modern birds such as Hesperornis and Ichthyornis were toothed, indicating that the loss of teeth occurred convergently in Confuciusornis and living birds. It is the oldest known bird to have a beak. It was named after the Chinese moral philosopher Confucius (551-479 B.C.E.).