Enantiornithes

Enantiornithes were an extinct group of mostly toothed birds that flourished during the Cretaceous. Many were adapted to life in trees, and the group vanished at the period’s end.

Avialae: Avialae is the theropod dinosaur group that includes birds and their closest extinct relatives. Enantiornithes are one major extinct radiation within this broader bird-line group.
Sinornis: Sinornis is a small Cretaceous enantiornithine known from fossils in China. Its fossils helped establish that early birds had diverse flight adaptations.
Bird flight: Bird flight is powered locomotion in which wings generate lift and thrust through repeated strokes. Wing and shoulder fossils help infer how enantiornithes flew.
Early Cretaceous: The Early Cretaceous is the first epoch of the Cretaceous Period, spanning roughly 145 to 100 million years ago. Some of the earliest known enantiornithines lived during this interval.
Cretaceous–Paleogene extinction event: The Cretaceous–Paleogene extinction event occurred about 66 million years ago and eliminated non-avian dinosaurs and many other organisms. Enantiornithes disappeared during this global extinction.
Bird: Birds are feathered, warm-blooded vertebrates descended from theropod dinosaurs. Enantiornithes were early birds, despite differences from the living bird body plan.
Eoalulavis: Eoalulavis is a Cretaceous enantiornithine from Spain, notable for a feathered alula. Its alula provides evidence of flight control in an early bird.
Alula: The alula is a small group of feathers attached to the first digit of a bird’s wing. Some enantiornithian fossils preserve this structure, associated with controlled slow flight.
Jehol Biota: The Jehol Biota is a fossil ecosystem of northeastern China, especially well preserved in Early Cretaceous rocks. Its deposits preserve many early enantiornithines, often with feathers and stomach contents.
Neornithes: Neornithes is the crown group containing all living birds and their descendants. Unlike enantiornithes, this bird lineage survived the end-Cretaceous extinction.

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