We thank Prof. Rong Jiayu for his advices in the research. We are grateful to Zhao Ridong, Lin Xianghong, and Han Shanqun for their great help in the field work. We thank Chen Yang, Nie Lei, and Zhou Zhengda for measuring geological section of the Qingshui Formation at the fossil locality, Feng Mingjuan for drawing the illustration Fig. 5. This work was supported by the Strategic Priority Research Program of CAS (XDB26000000), National Natural Science Foundation of China (41972006, 42072026), Key Research Program of Frontier Sciences, CAS (QYZDB-SSW-DQC040), and National Program for Support of Topnotch Young Professionals (W02070206).