Chordata Bateson, 1885 - chordates
   Class Elasmobranchii Bonaparte, 1838 see Subclass Elasmobranchii Bonaparte, 1838
     Subclass Selachii see Subdivision Selachii
       Order Cestraciontes
         Suborder †Janassides
           [Family †Petalodontidae Newberry & Worthen, 1866]