Chordata Bateson, 1885 - chordates 1 Class Leptocardii [monotypic] see Subphylum Cephalochordata Owen, 1846 2 Class Marsipobranchii see Class Cyclostomata 3 Class †Ostracophori 4 Class †Arthrodira Woodward, 1891 - arthrodires see Order Arthrodiriformes 5 Class Elasmobranchii Bonaparte, 1838 see Subclass Elasmobranchii Bonaparte, 1838 6 Class Pisces Linnaeus, 1758 see Superclass Pisces Linnaeus, 1758