The days of creative license in applying colors to dinosaurs may soon come to an end.
Scientists, eager to unlock true representations of long-extinct species, have recently discovered biomarkers in the feathers of birds that could also be used in the analysis of ancient fossilized specimens. The pioneering research, led by scientists at the University of Manchester and published in this month's Scientific Reports journal, focused on melanin, the dominant pigment in the skin, hair and feathers of mammals and birds.
"Melanin is a very important component in biology, but its exact chemistry is still not precisely known, especially as to how metals such as calcium, copper and zinc interact with it," Nick Edwards, a post-doctoral research assistant at the University of Manchester and the lead author of the study, told PhysOrg. "Here we have used a new approach to probe these components of melanin and have found that there are subtle but measurable differences between the different types of melanin with regards to certain elements."
To better understand how melanin imbues either a black/dark brown color (called eumelanin) or a reddish/yellow hue (called pheomelanin), the researchers analyzed the discarded feathers of the Harris hawk, red-tailed hawk, kestrel and barn owl. These four birds of prey were chosen both for their wide range of coloration and global distribution.
Using a synchrotron X-ray machine, the researchers were able to show that the distribution of certain elements like calcium, copper and zinc is controlled by the various shades of melanin in feathers. Analyzing how these elements are arranged in the preserved melanin of fossils could potentially offer critical hints on pigment patterns in biological tissues.
"Synchrotron X-ray analyses may now be used to produce more accurate and reliable pigment reconstructions in fossil organisms, including cases where the optical and structural fidelity of the biological tissues has been compromised through degradation processes," the researchers write.
The breakthrough comes less than a week after scientists at the University of Bristol unveiled what's being called the most life-like reconstruction of a dinosaur ever created. To bring the pigments of the 120-million Psittacosaurus (or "parrot lizard") to life, the researchers studied the well-preserved melanin present in a fossilized specimen from China.
"The fossil, which is on public display at the Senckenberg Museum of Natural History in Germany, preserves clear countershading, which has been shown to function by counter-illuminating shadows on a body, thus making an animal appear optically flat to the eye of the beholder," lead researcher Jakob Vinther said in a press release.
Unfortunately, as the video below explains, the fossil of Psittacosaurus was covered in a thick layer of varnish, complicating any future efforts to chemically analyze its color structure.