Ambiortus Kurochkin, 1982
Ambiortus is a prehistoric bird genus. The only known species, Ambiortus dementjevi, lived about 130 million years ago[verification needed] during the Early Cretaceous in today's Mongolia.
It belongs to the Ornithurae, which include the living birds, their ancestors, and some extinct Mesozoic groups like the toothed Hesperornithes and Ichthyornis. Among these, it appears to be fairly ancestral, similar to the better-known and slightly younger Gansus yumenensis. These taxa suggest that the ancestors of the birds of our time had separated from the Enantiornithes (the dominant subclass of Mesozoic birds), not too long after the times of Archaeopteryx.
The family Ambiortidae is sometimes used for this bird, especially if it is considered a close relative of the much younger Apsaravis which is then included therein. It is not at all likely however that these two are particularly closely related, and most authors simply consider it a basal ornithurine.
1. ^ a b Mortimer (2004)
* Mortimer, Michael (2004): The Theropod Database: Phylogeny of taxa. Retrieved 2008-AUG-14.
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