Chordata Bateson, 1885 - chordates
   Class †Arthrodira Woodward, 1891 - arthrodires see Order Arthrodiriformes Grande & Eastman, 1986
     1 Order †Stegophthalami see Class Placodermi McCoy, 1848
     2 Order †Temnothoraci [monotypic] see Order Antiarchiformes Grande & Eastman, 1986
     3 Order †Arthrothoraci see Order Arthrodiriformes Grande & Eastman, 1986