It is widely acknowledged the anatomy of bird wings is similar to the hands of Triassic theropod dinosaurs but cause of the debate was which digits stemmed the evolutional growth in bird wings.

The anatomy of the hand shows these come from enantiornithine birds, a major group in the Cretaceous, but which died out at the same time as the dinosaurs, 66 million years ago.

What’s more, the new findings might elucidate a feature of bird anatomy. They suggest that the hand wing, one of the two major wing structures, may be specialized to generate leading-edge ...

image: Scientists develop new index to understand how ancestors of modern birds used their wings based on the strength of the coracoid bone (shown in red) and the animal’s body mass view more ...

They can climb onto other animals to drink their blood, pluck insects from leaves or hover to drink nectar from tropical flowers, all of which require distinctive wing designs.

Leg-wing cooperation in baby birds, dinosaurs is key transition in origin of flight X-ray analysis finds that young birds can flap like adults despite rudimentary flight anatomy ...

They found that a gene called Nkx2.5 is turned on during the development of wings in emu embryos, but not in chickens or other birds, leading to greatly reduced wings.