Parent taxon: Neornithes according to B. C. Livezey and R. L. Zusi 2007
See also Carroll 1988, Clarke et al. 2005, Kurochkin 2000, Lindow and Dyke 2006, Mayr 2009, Mayr 2022, Meyer and Zardoya 2003, Nesbitt and Clarke 2016 and Slack et al. 2006
Sister taxa: Aequornithes, Alectromorphae, Cariamiformes, Cathartiformes, Colymbomorphae, Coraciomorphae, Eurypygiformes, Galbuliformes, Leptosomiformes, Lonchodytes pterygius, Mesitornithiformes, Neognathae, Odontognathae, Otidiformes, Pelargomorphae, Phoenicopteriformes, Picocoraciae, Pterocliformes
Subtaxa: Aepyornithiformes Ambiortiformes Crypturi Eremopezidae Lithornidae Lithornithidae Medioolithidae Palaeocursornithiformes Patagopterygiformes Ratitae Remiornithidae Remiornithiformes Rheiformes Struthioniformes