Chordata Bateson, 1885 - chordates Class Elasmobranchii Bonaparte, 1838 see Subclass Elasmobranchii Bonaparte, 1838 Subclass Selachii see Subdivision Selachii Order †Acanthodei Gunnell, 1933 see Class Acanthodii Owen, 1846 Family †Diplacanthidae Woodward, 1891