Alexornis

Alexornis is a genus of enantiornithine birds from the Bocana Roja Formation of Baja California, Mexico. This geological formation has been dated to the late Cretaceous period, and more specifically to the Campanian age, about 73 mya. The type and only known species is Alexornis antecedens. Its name means "Alex's ancestral bird"; Alexornis from the given name of ornithologist Alexander Wetmore + Ancient Greekornis, "bird", and antecedens, Latin for "going before" or "ancestral".

A. antecedens is known only from a single fragmentary skeleton including shoulder, wing, and leg bones, but lacking a skull. It was about the size of a sparrow. The specimen was discovered in 1971 and described and named in 1976 by Pierce Brodkorb. Brodkorb considered the species to be similar to some modern birds, and at the time, recognized it as one of the only known Cretaceous "land birds" after Gobipteryx minuta.