The good thing about amber fossils I that they are in 3D. This has allowed scientists to identify soft bone and cartilage, but most important, they have seen the presence of Barbules.
Barbules are structures found on birds that enable feathers to a structure that enable feathers to link together forming an insulator surface.
The presence of this structure in the fossil shows that dinosaurs did not just have a section of their bodies with feathers but their whole bodies.
"You get really exceptional preservation because it's in amber and it's in 3D," says Pete Makovicky, a curator of dinosaurs at the Field Museum of Natural History. "That gives an ability to really understand these structures, both in extreme detail and also in three dimensions."
Barbules present so early distorts the theory that feathers first appeared as strips in sections of the body. But the discovery shows that they may have appeared all at once.
"It's not like it characterizes all feathers, it's one snapshot in time," says Pete Makovicky. "It gives us a hint that some of the decay products from the blood are still trapped within the carbon layer that represents the skin."