After Motani, 1998, 1999, Nicholls & Manabe, 2001, and Fischer, Maisch, Naish, Kosma, Liston, Joger, Krüger, Pérez, Tainsh & Appleby, 2012

<==o †Euichthyosauria Motani, 1999
   |?- †Guizhouichthyosaurus tangae Cao & Luo, 2000 [Cymbospondylus asiaticus Li & You, 2002; Panjiangsaurus epicharis Chen & Chang, 2003]
   |--o †Teretocnemidae Maisch & Matzke, 2000
   |  |-- †Qianichthyosaurus zhoui Li, 1999
   |  `--o †Teretocnemus Merriam, 1903
   |     |-- †T. californicus Merriam, 1903
   |     `-- †T. zitteli ( Merriam, 1903) Motani, 1999c [Leptocheirus, Merriamia zitteli ( Merriam, 1903)]
   `--+-- †Californosaurus perrini Kuhn, 1934 [Delphinosaurus]
      `--o †Parvipelvia Motani, 1999
         |-- †Macgovania janiceps () Motani [“Ichthyosaurus” janiceps]
         `--+-- †Hudsonelpidia brevirostris McGowan, 1995
            `--+-- †Suevoleviathan disinteger Maisch, 1998
               `--+--o †Temnodontosaurus Lydekker, 1889
                  |  |-- T. eurycephalus
                  |  |-- T. nuertingensis (v. Huene, 1931)
                  |  `-- T. platyodon [incl. T. risor]
                  |--o †Eurhinosauridae [Leptonectidae Maisch, 1998; Eurhinosauria Motani, 1999]
                  |  |--o †Leptonectes McGowan, 1996
                  |  |  |-- †L. tenuirostris (Conybeare, 1822) McGowan, 1996 [Ichthyosaurus tenuirostris Conybeare, 1822]
                  |  |  |-- †L. solei (McGowan, 1993) McGowan, 1996
                  |  |  `-- †L. moorei McGowan & Milner, 1999
                  |  `--o †Eurhinosaurus Abel, 1909 sensu Maisch & Matzke, 2000
                  |     |-- †Eurhinosaurus longirostris (Owen & Jaeger, in Jaeger, 1856) Abel, 1909
                  |     `-- †Excalibosaurus costini McGowan, 1986 [Eurhinosaurus costini (McGowan, 1986) Maisch & Matzke, 2000]
                  `--o †Thunnosauria Motani, 1999 (ichthyosaurs with tuna-like tailfin)
                     |--o †Ichthyosaurus de la Beche & Conybeare, 1821 [Proteosaurus; Eurypterygius] L. Jur. Eu. Gr. [Ichthyosauridae]
                     |  |-- †I. conybeari
                     |  |-- †I. communis
                     |  `-- †I. breviceps
                     `--+--o †Stenopterygius Jaekel, 1904 [Stenopterygidae]
                        |  |-- †S. hauffianus
                        |  |-- †S. megacephalus
                        |  |-- †S. megalorhinus
                        |  |-- †S. longipes
                        |  |-- †S. macrophasma
                        |  |-- †S. cuneiceps
                        |  |-- †S. longifrons
                        |  |-- †S. acutirostris
                        |  `-- †S. quadriscissus
                        `--+-- †Chacaicosaurus cayi Fernández, 1994
                           `-- †Ophthalmosauria Baur, 1887 sensu Motani, 1998

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