The upper Yixian is dated considerably later than the lower, at about 122 million years ago. Despite this, the two units share many of the same dinosaur fauna, including Sinosauropteryx prima and Confuciusornis sanctus. The upper Yixian comprises the Dawangzhangzi and Jingangshan beds, as well as the (probably) contemporary Qiaotou beds of the Huajiying Formation.