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
   |  |--o †Qianichthyosaurus Li, 1999
   |  |  |-- †Q. zhoui Li, 1999
   |  |  `?- †Q. xingyiensis
   |  `--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 [=? “Leptopterygius” disinteger Huene, 1926]
               `--o †Neoichthyosauria Sander, 2000
                  |?- †Dearcmhara shawcrossi Brusatte, Young, Challands, Clark, Fischer, Fraser, Liston, MacFadyen, Ross, Walsh & Wilkinson, 2015
                  |--o †Temnodontosaurus Lydekker, 1889 [Ichthyosaurus Owen 1888; Leptopteryius v. Huene, 1922]
                  |  |-- †T. platyodon (Conybeare, 1822) [Ichthyosaurus lonchiodon Owen, 1888; incl. T. risor McGowan, 1974]
                  |  |-- †T. eurycephalus McGowan, 1974
                  |  |-- †T. burgundiae (Gaudry, 1892) McGowan, 1996a [Leptopterygius burgundiae Gaudry, 1892]
                  |  |?- †T. nuertingensis (v. Huene, 1931) [juveline]
                  |  |-- †T. trigonodon (Theodori, 1843) [Ichthyosaurus trigonodon Theodori, 1843]
                  |  |-- †T. acutirostris (Owen, 1840) [Leptopteryius acutirostris (Owen, 1840)]
                  |  `-- †T. azerguensis Martin, Fischer, Vincent & Suan, 2012
                  |--o †Eurhinosauridae [Leptopterygiidae Kuhn, 1934; Leptonectidae Maisch, 1998; Eurhinosauria Motani, 1999; ]
                  |  |--o †Leptonectes McGowan, 1996a [Leptopterygius Huene, 1922 (non Leptopterygius Troschel, 1860 (a fish))]
                  |  |  |-- †L. tenuirostris (Conybeare, 1822) McGowan, 1996a [Ichthyosaurus tenuirostris Conybeare, 1822; Leptopterygius tenuirostris (Conybeare) Huene, 1922; Ichthyosaurus tenuirostris Conybeare, McGowan, 1974; Leptopterygius tenuirostris (Conybeare), Appleby, 1979]
                  |  |  |-- †L. solei (McGowan, 1993) McGowan, 1996 [Leptopterygius solei McGowan, 1993]
                  |  |  `-- †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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