In 2015, the group was defined as "the most inclusive clade containing Caudipteryx zoui but not Oviraptor philoceratops and Caenagnathus collinsi".
The group was formally established in 2015 by identifying a broad category that includes Caudipteryx zoui, while excluding two other dinosaurs: Oviraptor philoceratops and Caenagnathus collinsi.