In addition to the front wings, Anchiornis had long, vaned feathers on the hind legs.
This has led many scientists to call Anchiornis a four-winged dinosaur, along with similar animals like Microraptor and Sapeornis.
However, the feathers on the hind legs in Anchiornis did not have the shape or arrangement expected from flight feathers, and it is likely that their primary role was in display rather than flight.

Anchiornis had very long legs, which is usually an indication that an animal is a strong runner.
However, the extensive leg feathers indicate that this may be a vestigial trait, as running animals tend to have reduced, not increased, hair or feathers on their legs.
Like most paravians, Anchiornis had four toes on the foot, with the third and fourth toes the longest.
The first toe, or hallux, was not reversed as in perching species.
The hindwings of Anchiornis were also shorter than those of Microraptor, and were made up of 12 to 13 flight feathers anchored to the tibia (lower leg) and 10 to 11 to the tarsus (upper foot).
Also unlike Microraptor, the hindwing feathers were longest closer to the body, with the foot feathers being short and directed downward, almost perpendicular to the foot bones.

Unlike many other paravians, the feet of Anchiornis (except for the claws) were completely covered in feathers, though these were much shorter than the ones making up the hindwing.
Some specimens have preserved scales on the toes, tarsus, and even lower leg (tibia), suggesting that scales existed beneath the feathers.
The underside of the toes were formed into fleshy pads with distinct creases at the joints.
The foot pads were covered in small, pebble-like scales.
Scales were also present on the top of the feet but these are very hard to see in all known fossils.
In addition to the front wings, Anchiornis had long, vaned feathers on the hind legs. This has led many scientists to call Anchiornis a four-winged dinosaur, along with similar animals like Microraptor and Sapeornis. However, the feathers on the hind legs in Anchiornis did not have the shape or arrangement expected from flight feathers, and it is likely that their primary role was in display rather than flight.
Anchiornis had very long legs, which is usually an indication that an animal is a strong runner. However, the extensive leg feathers indicate that this may be a vestigial trait, as running animals tend to have reduced, not increased, hair or feathers on their legs. Like most paravians, Anchiornis had four toes on the foot, with the third and fourth toes the longest. The first toe, or hallux, was not reversed as in perching species. The hindwings of Anchiornis were also shorter than those of Microraptor, and were made up of 12 to 13 flight feathers anchored to the tibia (lower leg) and 10 to 11 to the tarsus (upper foot). Also unlike Microraptor, the hindwing feathers were longest closer to the body, with the foot feathers being short and directed downward, almost perpendicular to the foot bones.
Unlike many other paravians, the feet of Anchiornis (except for the claws) were completely covered in feathers, though these were much shorter than the ones making up the hindwing. Some specimens have preserved scales on the toes, tarsus, and even lower leg (tibia), suggesting that scales existed beneath the feathers. The underside of the toes were formed into fleshy pads with distinct creases at the joints. The foot pads were covered in small, pebble-like scales. Scales were also present on the top of the feet but these are very hard to see in all known fossils.
Anchiornis