In 2012, researchers traveled to China to study the fossils of dinosaurs from the Cretaceous era. For the first time, these 125-year-old fossils were examined under electron microscopes and subjected to chemical analysis. What they found was unexpected.
Dr. Maria McNamara from University College Cork reports that the team was initially focused on the feathers of the ancient animals. They kept finding “white blobs” between the feathers, and they became a distraction so the team worked to identify exactly what they were. They considered whether they could be fragments of shells or reptile skin, but the substance wasn’t consistent with either of those things. Then came the discovery that was the key. The blobs contained keratin and corneocytes and had a structure that’s identical to the skin of modern birds. BBC reports that this discovery led researchers to surmise that these prehistoric creatures did not shed their skin all at once like a reptile, but rather, they shed it in small pieces. This was a discovery of dinosaur dandruff.
Dr. McNamara commented that “this is the only fossil dandruff known. Until now we’ve had no evidence for how dinosaurs shed their skin.”
Another member of the team, Professor Mike Benton, said the following.
“It’s unusual to be able to study the skin of a dinosaur, and the fact this is dandruff proves the dinosaur was not shedding its whole skin like a modern lizard or snake but losing skin fragments from between its feathers.”
Researchers believe that dinosaurs likely developed skin during the middle of the Jurassic period. McNamara explained that “even though they are in the early stages of feather evolution, they have already adapted their skin to this more modern structure.”
They did, however, find one significant difference. The prehistoric creatures had a different kind of fat in their dandruff cells than today’s birds. The fat in today’s birds creates a cooling effect in flight. Without this fat, ancient feathered animals probably were not able to fly far. It could also mean that they had a lower body temperature than modern birds, falling somewhere between cold-blooded reptiles and warm-blooded birds. The Guardian reports that for these animals, feathers served as insulation, camouflage, and a way to attract the opposite sex.
A microraptor, beipiaosaurus, sinornithosaurus, and confuciusornis were examined. A microraptor was about the size of a crow and fed on meat. It had feathers on all four of its limbs. The beipiaosaurus and sinornithosaurus were twice the size of a microraptor when fully grown.