14 DAY TRIAL // Scientists at the University of Texas in Austin (UTA) were recently able to demonstrate in a new study that dinosaurs had very bright plumages, very similar or nearly identical to the ones modern-day birds sport. The research answers a long-standing question about the evolution of feathers.
The research group found out that feather color variability most likely arose with feathers themselves; in other words, it is not a function of evolution or natural selection. The work revealed the existence of structures responsible for feather colors in ancient lizard samples.
The fact that many dinosaurs most likely sported feathers was discovered in the 1990s, and subsequent works have gone a long way towards confirming this hypothesis. Additionally, paleontologists now know that birds are the only living branch of the dinosaur family, having survived the Cretaceous-Paleogene extinction event, some 65 million years ago.
UTA scientist and study coauthor Julia Clarke argues that feathered dinosaurs are very likely to have had brightly colored plumages. Details of the investigation are published in a recent issue of the top scientific journal Nature.
Giant lizards likely to have had feathers include Maniraptoran dinosaurs, such as the famous oviraptors and dromaeosaurs. All of these creatures therefore featured the melanocortin system, which contains genes that code the color of skin, hair and feathers.
This system also plays an important role in sexual function, metabolism and inflammation. As such, this discovery led scientists to propose that a significant change occurred in the bodies of feathered dinosaurs, as opposed to their naked cousins, Time reports.
“We hypothesize that what we’re seeing is a big physiological shift in dinosaurs, a change that has other implications than just the color of feathers,” Clarke explains. In the new study, the expert and her team were able to identify microscopic structures called melanosomes.
These small-scale structures can be found in developing hair or skin, and play a significant role in controlling the chemistry of the pigments that color these organs. For example, round melanosomes are more common in red hair and feathers, whereas longer melanosomes produce darker colors.
Upon analyzing a large number of fossils, the team found different melanosomes formations in dinosaurs that are known to have sported feathers. Those that did not display any trace of the microscopic structure. However, the team admits that more work is needed to clear up these issues.
“When you’re looking back 150 million years through a dirty lens, causality can be hard to get at. We’ve got a lot more to figure out.” Clarke concludes.