Like other early paravians, Anchiornis had large wings made up of pennaceous feathers attached to the arm and hand.
The wing of Anchiornis was composed of 11 primary feathers and 10 secondary feathers.
The primary feathers in Anchiornis were about as long as the secondaries, and formed a rounded wing.
The wing feathers had curved but symmetrical central quills, with small and thin relative size, and rounded tips, all indicating poor aerodynamic ability.
In the related dinosaurs Microraptor and Archaeopteryx, the longest wing feathers were closest to the tip of the wing, making the wings appear relatively long and pointed.
However, in Anchiornis, the longest wing feathers were those nearest the wrist, making the wing broadest in the middle and tapering near the tip for a more rounded, less flight-adapted profile.

Like other maniraptorans, Anchiornis had a propatagium, a flap of skin connecting the wrist to the shoulder and rounding out the front edge of the wing.
In Anchiornis, this part of the wing was covered in covert feathers which smoothed the wing and covered the gaps between the larger primary and secondary feathers.
However, unlike modern birds, the covert feathers of Anchiornis were not arranged in tracts or rows.
The arrangement of the covert feathers was also more primitive in Anchiornis than in birds and more advanced paravians.
In modern birds, the coverts usually cover only the upper portion of the wing, with most of the wing surface made up of uncovered flight feathers.
In some Anchiornis fossils, on the other hand, several layers of covert feathers seem to extend down to cover most of the wing's surface, so that the wing is essentially made of multiple layers of feathers, rather than a layer of broad feathers with only their bases hidden by layers of coverts.
This multi-layered wing arrangement might have helped strengthen the wing, considering that the primary and secondary feathers themselves were narrow and weak.

The wing included three clawed fingers; however, unlike in some more primitive theropods, the longest two fingers were not separate, but were bound together by the skin and other tissue forming the wing, so Anchiornis was functionally two-fingered.
These bound fingers were incorporated into a post-patagium, or flap of skin and other tissues that helped support the bases of the main wing feathers.
Like the toes, the skin around the bottom of the fingers was covered in tiny, rounded scales.
Unlike the toes, the flesh around the underside of the finger bones was twice as thick as the bones themselves and lacked distinct pads; instead, the fingers were straight and smooth without any major creases at the joints.
Scales and skin around the fingers is very rarely preserved in fossils of early pennaraptorans, the only notable exceptions being Anchiornis and Caudipteryx, which had similar thick, scaly fingers associated with its wings.
Like other early paravians, Anchiornis had large wings made up of pennaceous feathers attached to the arm and hand. The wing of Anchiornis was composed of 11 primary feathers and 10 secondary feathers. The primary feathers in Anchiornis were about as long as the secondaries, and formed a rounded wing. The wing feathers had curved but symmetrical central quills, with small and thin relative size, and rounded tips, all indicating poor aerodynamic ability. In the related dinosaurs Microraptor and Archaeopteryx, the longest wing feathers were closest to the tip of the wing, making the wings appear relatively long and pointed. However, in Anchiornis, the longest wing feathers were those nearest the wrist, making the wing broadest in the middle and tapering near the tip for a more rounded, less flight-adapted profile.
Like other maniraptorans, Anchiornis had a propatagium, a flap of skin connecting the wrist to the shoulder and rounding out the front edge of the wing. In Anchiornis, this part of the wing was covered in covert feathers which smoothed the wing and covered the gaps between the larger primary and secondary feathers. However, unlike modern birds, the covert feathers of Anchiornis were not arranged in tracts or rows. The arrangement of the covert feathers was also more primitive in Anchiornis than in birds and more advanced paravians. In modern birds, the coverts usually cover only the upper portion of the wing, with most of the wing surface made up of uncovered flight feathers. In some Anchiornis fossils, on the other hand, several layers of covert feathers seem to extend down to cover most of the wing's surface, so that the wing is essentially made of multiple layers of feathers, rather than a layer of broad feathers with only their bases hidden by layers of coverts. This multi-layered wing arrangement might have helped strengthen the wing, considering that the primary and secondary feathers themselves were narrow and weak.
The wing included three clawed fingers; however, unlike in some more primitive theropods, the longest two fingers were not separate, but were bound together by the skin and other tissue forming the wing, so Anchiornis was functionally two-fingered. These bound fingers were incorporated into a post-patagium, or flap of skin and other tissues that helped support the bases of the main wing feathers. Like the toes, the skin around the bottom of the fingers was covered in tiny, rounded scales. Unlike the toes, the flesh around the underside of the finger bones was twice as thick as the bones themselves and lacked distinct pads; instead, the fingers were straight and smooth without any major creases at the joints. Scales and skin around the fingers is very rarely preserved in fossils of early pennaraptorans, the only notable exceptions being Anchiornis and Caudipteryx, which had similar thick, scaly fingers associated with its wings.
Anchiornis