Gansuidae

Gansus is a genus of aquatic avialans that lived during the Aptian age of the Early Cretaceous (Aptian-Albian) period in what are now Gansu and Liaoning provinces, western China. The rock layers from which their fossils have been recovered are dated to 120 million years ago. It was first described in 1984 on the basis of an isolated left leg. It is the oldest-known member of the Ornithurae, the group which includes modern birds (Neornithes) and extinct related groups, such as Ichthyornis and Hesperornithes.

Shuilingornis (meaning "pretty and vivid bird") is an extinct genus of gansuid euornithean birds from the Early Cretaceous Jiufotang Formation of China. The genus contains a single species, S. angelai, known from a nearly complete articulated skeleton. As a member of the Gansuidae, Shuilingornis represents one of the earliest known birds known to demonstrate semi-aquatic adaptations.

Changzuiornis is an extinct genus of ornithuromorph bird from the Early Cretaceous of present-day China. It contains a single species, C. ahgmi.