Feathers are a rarity in the fossil record, and three-dimensional feathers are even rarer. Yet for the first time ever, researchers working in Myanmar have discovered a three-dimensional fossil of two bird wings and attached feathers preserved in amber. The study was led by Lida Xing of the China University of Geosciences and was published in the June 28 edition of the scientific journal Nature Communications. The specimen consists of not just the feathers of an extinct bird but also the muscular and skeletal structure of the creature’s arm plus the bird’s clawed hands.
Team member and coauthor Ryan C. McKellar of Canada's Royal Saskatchewan Museum had once described bird and dinosaur feathers in Canadian amber, but they pale in comparison to the Burmese find. The Canadian find was not an articulated specimen, with the feathers being an isolated element. They were not attached to the animal's body.
The impressive level of preservation in the Burmese amber means that Xing’s team could tell that the animal had asymmetrical feathers for powered flight. Yet the small size and poor development of the flight feathers suggested that the birds were just hatchlings when they died. They also belonged to a large group of extinct, primitive birds called the enantiornithines. This was an abundant and diverse group unique to the dinosaur age, spanning the entirety of the Cretaceous, with fossil finds as far apart as Spain, China and North America.