A new X-ray study finds that modern-day bird feathers have more in common with dinosaur feathers than experts previously assumed, including a comparable protein makeup.
The discovery sheds new light on how feathers evolved over hundreds of millions of years.
Remnants of corneous beta-proteins
According to a study published Sept. 21 in the journal Nature Ecology and Evolution, paleontologists at University College Cork (UCC) in Ireland examined feathers from three ancient animals: Sinornithosaurus, a 125 million-year-old nonavian dinosaur found in China; Confuciusornis, a 125 million-year-old early bird also found in China; and an unspecified species that lived in what is now the Green River Formation in Wyoming 50 million years ago.
After analyzing the ancient feathers with X-rays and infrared light, the researchers discovered remnants of corneous beta-proteins (CBPs), formerly known as beta-keratins, which are proteins required for strengthening feathers for flight.
After that, the international team of experts examined feathers from modern birds, such as zebra finches (Taeniopygia), and discovered that they had a similar chemical structure.
The scientists also carried out additional experiments that mimicked the temperatures that the fossils were exposed to over time.
These tests demonstrated that, as opposed to being a component of the feather during life, alpha-proteins can develop in a fossil as a result of the fossilization process.
The study revealed that although some fossil feathers contain large amounts of alpha-proteins, it is likely that these proteins were not there at the time the feathers were produced.
They developed as a result of the intense heat that fossils go through.
Prior to this finding, experts believed that ancient animal feathers had an entirely different protein composition and were mostly made up of alpha proteins, which aren't as strong as corneous beta proteins.
"Previous tests on dinosaur feathers, though, found mostly alpha-proteins. Our experiments can now explain this weird chemistry as the result of protein degradation during the fossilization process. So although some fossil feathers do preserve traces of the original beta-proteins, other fossil feathers are damaged and tell us a false narrative about feather evolution," said Dr. Tiffany Slater, co-author of the study.
Read Also: Smallest Dinosaur Discovered in Amber
Evolution of ancient feathers
This new understanding not only demonstrates that proteins may be retained in the fossil record for up to 125 million years, but it also sheds new light on the evolution of ancient feathers by "pushing the time scales a lot further than what we thought."
The research helps rewrite the story by demonstrating that the very first components needed for powered flight existed at least 125 million years ago.
"We're developing new tools to understand what happens during fossilization and unlock the chemical secrets of fossils. This will give us exciting new insights into the evolution of important tissues and their biomolecules," said Prof. Maria McNamara, co-author of the study.
Recently, a fossil of a dinosaur from the Jurassic Period named Fujianvenator prodigiosus, which gives insight on a crucial evolutionary stage in the formation of birds, was discovered in the Fujian Province.
The pheasant-sized dinosaur with long lower legs existed in southeast China's Fujian province about 148-150 million years ago, according to experts.
Related Article: 'Living Dinosaurs': Birds Posses Dinosaur-Like Features Before They Hatch from Their Eggs
Related Video: