Dinosaur-Era Bird Wings Preserved in Amber

The fossils include the first examples of hair follicles and feather arrangements from the Cretaceous, revealing that both were about the same as they are today.

Photo: A 99-million-year-old wing from a toothed bird preserved in amber. The specimen includes a claw and a pale spot on the plumage. Credit: Royal Saskatchewan Museum (RSM/R.C. McKellar)

Two wings preserved in amber from dinosaur-era, toothed birds have just been discovered, a new study reports.

The 99-million-year-old wings -- nicknamed "angel wings" and "Rose" by the researchers -- include the first examples of hair follicles and feather arrangements from the Cretaceous Period, according to the paper, published in the journal Nature Communications.

The wings belonged to enantiornithine birds, a lineage that died out with dinosaurs at the end of the Cretaceous (145.5–65.5 million years ago).

RELATED: Prehistoric Coffee Ancestor Found in Amber

"The discovery of enantiornithine wings preserved in Burmese amber provides a unique opportunity to observe these animals frozen in time with a new level of detail," co-author Ryan McKellar, curator of invertebrate paleontology at the Royal Saskatchewan Museum, told Discovery News. "These specimens are as close as we have ever come to examining parts of these extinct, toothed birds 'in the flesh.'"

McKellar, lead author Lida Xing and their colleagues found the fossils at a site in the Kachin Province of Myanmar. They examined the structure and arrangement of the bones and feathers in the fossils using techniques such as synchrotron X-ray micro CT scanning.

The scientists also compared the fossils with other prehistoric bird remains, which led to the enantiornithine identification. Usually only isolated feathers are found in Cretaceous amber, leaving uncertainty about the feather bearer.

The researchers were also able to determine that the wings belonged to juvenile birds.

"The samples confirm that juvenile enantiornithines possessed adult-like plumage while they were still hummingbird-sized hatchlings, and that the arrangement and structure of these feathers were quite similar to those found in modern birds," McKellar said.

RELATED: Dinosaur Feathers Found in Amber: Photos

He says the feathers were so well preserved that they still retain color.

"The structure of feathers can be observed down to the finest branches (barbules)," McKellar explained, "and the preserved pigmentation provides us with a picture of dark brown wings with a pale spot or band on their upper surface, and pale or white undersides.

"I am particularly excited about this project because it provides the first opportunity to observe feathers in amber alongside skeletal material and identify the source with confidence."

WATCH VIDEO: Why Can't Some Birds Fly?