After Caldwell, 1999, Bell, 1994

<==o Pythonomorpha Cope, 1869 sensu Caldwell, 1999 (käärmeet & meriliskot; snakes & mosasaurids) [traditionally placed here, for most recent view, see Squamata]
   |?- †Carentonosaurus mineaui Rage & Néraudeau, 2004; U.Cret. WEu.
   |?-o †Coniasaurus Owen, 1850
   |  |-- †C. crassidens Owen, 1850
   |  `-- †C. gracilodens Galdwell, 1999
   |?- †Mesoleptos zendrini Cornelia & Chiozza, 1852
   `--+-- Serpentes Linnaeus, 1758 [Ophidia sensu Lee & Caldwell, 2000] (käärmeet)
      `--o ††Mosasauroidea Camp, 1923 sensu Bell, 1994 and Caldwell, 2000 (meriliskot)
         |--o †Dolichosauridae Gervais, 1852 (“pienmeriliskot”)
         |  |?- †Eidolosaurus trauthi Nopcsa, 1923
         |  `--+-- †Pontosaurus lesinensis Kornhuber, 1873 [Hydrosaurus]
         |     `--+-- †Dolichosaurus longicollis Owen, 1850
         |        `--o †Acteosaurus von Meyer, 1860 [Adriosaurus]
         |           |-- †A. tommasinii von Meyer, 1860
         |           `-- †A. crassicostatus Calligaris, 1993
         `--+-- †Mosasauridae (“suurmeriliskot”)
            `--o †Aigialosauridae Kramberger, 1892 (“vanhameriliskot”)
               |--o †Aigialosaurus Kramberger, 1892
               |  |-- †A. dalmaticus Kramberger, 1892
               |  `-- †A. bucchichi (Kornhuber, 1901) [Opetiosaurus bucchichi Kornhuber, 1901; Aigialosaurus novaki Kramberger, 1892]
               |-- †Carsosaurus marchesetti Kornhuber, 1893
               |?- †Proaigialosaurus huenei Kuhn, 1958 [nomen dubium, specimen lost]
               |-- †Aigialosauridae genera et species indet. [Trieste specimen]
               |-- †Aigialosauridae genera et species indet. [Dallas specimen]
               `-- †Aigialosauridae genera et species indet. [Yale specimen]

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