Avian skulls represent a diverse ornithuromorph fauna from the Lower Cretaceous Xiagou Formation, Gansu Province, China
Jingmai K. O'Connor, Thomas A. Stidham, Jerald D. Harris, Matthew C. Lamanna, Alida M. Bailleul, Han Hu, Min Wang, and Hai‐Lu You
Journal of Systematics and Evolution . 2022, (5): 1172 -1198 .  DOI: 10.1111/jse.12823