Phylum Chordata Bateson, 1885 - chordates Subphylum Vertebrata Cuvier, 1812 - vertebrates Pisces 1 Class †Pituriaspida see Order Pituriaspida 2 Class Mixini see Class Myxini 3 Class †Pteraspidomorphi Goodrich, 1909 4 Class Cephalaspidomorphi 5 Class †Placodermi McCoy, 1848 6 Class Chondrichthyes Huxley, 1880 - cartilaginous fishes 7 Class †Acanthodii Owen, 1846 8 Class Actinopterygii Woodward, 1891 - ray-finned fishes 9 Class Sarcopterygii Romer, 1955 - lobe-finned fishes and tetrapods see Clade Sarcopterygii Romer, 1955