enantiornitheans
Enantiornitheans, also called enantiornithines, are an extinct clade of birds within Avialae that flourished during the Cretaceous period. They were among the most diverse and widespread avialans of the Mesozoic, with fossils found on several continents and a particularly well-represented record in the Jehol Biota of East Asia. They persisted until the end of the Cretaceous, when they went extinct in the mass extinction event that also eliminated non-avian dinosaurs.
A defining feature of enantiornitheans is the reversed, or opposite, articulation of the shoulder girdle compared
Ecologically, enantiornitheans occupied diverse niches. They were generally arboreal and insectivorous, but the group included species
The fossil record is especially rich in China and other parts of the world, providing important insights