Ornithurae

Ornithurae (meaning 'bird tails' in Greek) is the name of a natural group which includes all modern birds as well as their extinct relatives with plough-shaped pygostyles (†Ichthyornis, †Hesperornithes, †Limenavis). This is a bone at the end of the tail which allows the tail feathers to fan and retract. Gansus, from the Lower Cretaceous of China is the earliest known at 110 million years ago.

Ornithurae
Scientific classification
Kingdom:	Animalia
Superorder:	Dinosauria
Order:	Saurischia
(unranked):	Avialae

Simple classification:

• Birds
  • Ornithurae
    • Neornithes: modern birds: the most recent common ancestor of all living birds (class Aves) and all its descendants.
      • Palaeognathae (tinamous and flightless ratites)
      • Neognathae (all other modern birds)

Ornithurae Media

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  Hesperornis BW (white background)

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  Life restoration of Ichthyornis dispar, a primitive seabird that lived in the Western Interior Seaway (North America)during the Late Cretaceous.

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  Life restoration of Vegavis iaai, a waterfowl relative that lived in the Antarctic Peninsula during the end of the Cretaceous period. Appearance is based on a 2017 study that linked Vegavis to the loon-like Polarornis.

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  Meyers grosses Konversations-Lexikon - ein Nachschlagewerk des allgemeinen Wissens (1908) (Antwerpener Breiftaube)