Subclass Avialae Gauthier, 1986 see Clade Avialae Gauthier 1986
Ref: B.C. Livezey & R.L. Zusi, 2007: 89; Count: [o] 31o;113f; ‡2o;6f; †11o;14f
   Infraclass Aves Linnaeus, 1758 see Subclass Aves Linnaeus, 1758
  Ref: B.C. Livezey & R.L. Zusi, 2007: 89; Count: [o] 31o;113f; ‡2o;6f; †11o;14f
     Parvclass †Ornithurae Haeckel, 1866 see Clade Ornithurae Haeckel 1866 [Gauthier 1986] {Chiappe 1991}
    Ref: B.C. Livezey & R.L. Zusi, 2007: 89; Count: [†f] †2o;2f
       Superorder †Odontoholomorphae Stejneger, 1885 see Clade Ornithurae Haeckel 1866 [Gauthier 1986] {Chiappe 1991}
      Ref: B.C. Livezey & R.L. Zusi, 2007: 89; Count: [†f] †2o;2f
         Order †Ichthyornithiformes Marsh, 1873
        Ref: B.C. Livezey & R.L. Zusi, 2007: 89; Count: [†f] †1f
           Family †Ichthyornithidae Marsh, 1873
          Ref: B.C. Livezey & R.L. Zusi, 2007: 89; Count: -