Ambiortus

  Scant information is available for this species.  A partial skeleton of the
  crow sized bird with feather impressions was found in Mongolia from
  Early Cretaceous lacustrine deposits.  The skull is unknown.  The phyletic
  position of Ambiortus is difficult to assess due to the large number of
  missing features.  Kurochkin (1985) refers to it as a true carinate bird
  with good powers of flight.