Chordata Bateson, 1885 - chordates
   Class Elasmobranchii Bonaparte, 1838 see Subclass Elasmobranchii Bonaparte, 1838
     Subclass Selachii see Subdivision Selachii
       Order Batoidei see Order Batoidea
         Suborder Masticura (Gill, 1872)
           Family Potamotrygonidae Garman, 1877 - river stingrays