Protopteryx

Protopteryx is one of the oldest and most primitive members of the group Enantiornithes, which were early birds that lived alongside dinosaurs.1

Its two central tail feathers were scalelike without barbs near the body, only having barbs at the tips. This is similar to the tail feathers of the modern red bird-of-paradise.12

Protopteryx was about the size of a modern starling, with a body length of only 10 centimetres (3.9 inches) not counting its long tail feathers.1

Its body was covered in three types of feathers: down feathers, flight feathers, and the long ribbon-like tail feathers.1

The down feathers of Protopteryx had flat, frayed tips instead of the hairlike barbs seen in modern birds.1

Protopteryx had a triosseal canal, a feature in the shoulder that helped with flight, and this is one of the earliest examples in birds.2