Lineage of Ichthyosauriformes
Ichthyosauriformes Ichthyosauromorpha Enaliosauria Pan-Testudines Archelosauria Reptilia Diapsida Romeriida Neoreptilia pan-Reptilia Amniota Pan-Amniota Tetrapoda pentadactyl pan-tetrapods hexadactyl pan-tetrapods Labyrinthodontia Stegocephali Elpistostegalia Panderichthyida Tristichopteriformes Eotetrapodiformes Osteolepidida pan-Tetrapoda Rhipidistia Sarcopterygii Osteichthyes Pan-Osteichthyes Gnathostomata maxillate vertebrates vertebrates with ventral nasal openings Apo-Gnathostomata Cephalaspidomorpha Pan-Gnathostomata Vertebrata pan-Vertebrata Olfactores Chordata pan-chordates with myomeres pan-chordates with branchial arches Vetulicolida pan-Chordata Nephrozoa Bilateria pan-Bilateria Parahoxozoa Myriazoa Metazoa pan-Metazoa