AVES
  |
NEORNITHES
  |
  +-PALEOGNATHS
  |   \-+--Struthioniformes
  |     |     \--Struthionidae (Ostriches)
  |     |
  |     \-+--Rheiformes
  |       |     \--Rheidae (Rheas)
  |       |
  |       \-+--+--+--Apterygiformes
  |         |  |  |    \--Apterygidae (Kiwis)
  |         |  |  \-?Aepyornithiformes
  |         |  |       \--Aepyornithidae (Elephant Birds) [extinct]
  |         |  |
  |         |  \--Casuariiformes
  |         |       \--+--Casuariidae (Cassowaries)
  |         |          \--Dromaiidae (Emus)
  |         |
  |         \-+--Dinornithiformes
  |           |    \--Dinornithidae (Moas) [extinct]
  |           |
  |           \--Tinamiformes
  |                \--Tinamidae (Tinamous)
  |
  \-NEOGNATHS
      |--GALLOANSERAE
      |
      \--NEOAVES
           |--METAVES
           \--CORONAVES