Class Reptilia Linnaeus, 1758 - reptiles
   Subclass †Euryapsida Colbert, 1945 see Subclass Diapsida Osborn, 1903
     Order †Sauropterygia Owen, 1860 see Superorder Sauropterygia Owen, 1860
       Suborder †Placodontia Owen, 1859
         1 Family †Helveticosauridae Peyer, 1955
         2 Family †Placodontidae Cope, 1871
         3 Family †Cyamodontidae Nopcsa, 1923
         4 Family †Henodontidae Huene, 1936