There is a reason why the T-Rex is green and the pterosaur has a yellow beak. And a new study promises to make it easier to find animal colors using fossil records.
By Ingrid Luisa
Oct 2, 2019, 7:01 pm – Posted Oct 2, 2019, 7:00 pm
Have you ever wondered how scientists determine the color of dinosaurs? Or other extinct animals no one has ever seen? It doesn't have much secret: to find out that T-Rex was greener and orange pterosaur researchers do fossil studies. Sometimes, in well-preserved specimens, traces of feathers and other structures can provide the exact colors of the animal. In most cases, however, paleontologists need to unravel a true puzzle by associating the fossil skeleton with that of other existing species and assessing the lifestyle of these animals.
Now, a new study by researchers at the University of Hong Kong Vertebrate Paleontology Laboratory has evaluated all methods of fossil color reconstruction and proposed using them to improve current results. “We evaluate everything we know about fossil and modern animal colors and use that knowledge to come up with a framework and improve the way we will reconstruct fossil colors in the future,” says Michael Pittman, author of the study.
According to the researchers, so far there is no formalized method for this because each fossil is a fossil: depending on preservation, the animals have kept fewer or more samples available for analysis, such as tissues or other body structures. But anthropologists have proposed a step-by-step approach that may be useful in all cases.
The first thing is to map the colors that already exist in the sample, if there is any visible pattern (stripes or spots, for example) or any clear hint of pigment. Then is the time to look for microstructures in the integuments (tissues), which often use melanin-based colors such as black, gray and brown, and can be identified with electron microscopy.
If nothing with melanin is detected, now is the time to use high tech chemical analysis techniques and to detect biomarkers of other pigments (such as carotenoids, porphyrins, pterines and flavins). Finally, after these detections, it is time to evaluate which colors are possible according to the physical characteristics of the animal, its behavior and the environment in which it lives – factors that influence its coloration.
Scientists say the procedure is quite effective. "This is the first study that not only critically evaluates currently available methods, but also provides a reliable and repeatable framework that covers all vertebrate pigment systems, not just melanin," says Pittman.