Chordata Bateson, 1885 - chordates
Count: -
   1 Class Leptocardii Müller, 1845 [monotypic] see Subphylum Cephalochordata Owen, 1846
  Count: [f] 1o;3f;1g
   2 Class Marsipobranchii see Class Cyclostomata Richards
  Count: [f] 2o;4f
   3 Class †Ostracophori
  Count: [†f] †5o;15f;7g;1s
   4 Class †Arthrodira Woodward, 1891 - arthrodires see Order Arthrodiriformes Grande & Eastman, 1986
  Count: [†f] †3o;9f;2g
   5 Class Elasmobranchii Bonaparte, 1838 see Subclass Elasmobranchii Bonaparte, 1838
  Count: [f†f] 7o;39f;5g; †4o;22f;4g
   6 Class Pisces Linnaeus, 1758 see Superclass Pisces Linnaeus, 1758
  Count: -