Full reference: J. A. Clarke. 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum of Natural History 286:1-179
Parent taxon: Aves according to J. A. Clarke 2004
Sister taxa: Accipitriformes, Aegotheliformes, Aletornis, Avimimiformes, Avipedidae, Callaeidae, Chaoyangornithidae, Charadriiformes, Colymbiformes, Emeidae, Eoaves, Eremopezidae, Gansuiformes, Gastornithiformes, Hwangsanipes, Ignotornidae, Jeholornithiformes, Jindongornipodidae, Koreanornipodidae, Liaoxiornithidae, Manu, Meliphagidae, Metornithes, Monarchidae, Mystiornithiformes, Neornithes, Odontornithes, Omnivoropterygiformes, Ornithothoraces, Ornithurae, Palaeoaves, Pansphenisciformes, Petroicidae, Proornis, Protoaviformes, Pygostylia, Rahona, Sapeornithiformes, Shandongornipodidae, Sphenisciformes, Stereornithes, Struthiones, Tatarornipes, Trisauropodiscidae, Tshulia, Tubinares, Turnagridae, Uhangrichnus, Zhongjianornis, Zhongornis
Subtaxa: Austinornis
Ecology: ground dwelling carnivore