The oldest fossilized dandruff has just been detected in a Microraptor, a species of tiny feathered dinosaurs that walked the Earth about 125 million years ago. Also, the studies on a couple of other ancient feathered dinosaurs, Beipiaosaurus and Sinornithosaurus, and on an ancient bird, commonly referred to as Confuciusornis, have also uncovered fragments of dandruff.
As opposed to modern-day reptiles which are shedding their superficial external skin layers in one single step, the ancient feathered dinosaurs look as if they have adjusted to shed their skin in very small dandruff-like flakes.
“It’s the only known fossil dandruff. So far, we had no evidence of how dinosaurs lost their skin,” explained Maria McNamara from University College Cork and leading researcher in the study.
Fossilized dandruff discovered in ancient feathered dinosaurs hints to a better understanding of these long-gone species
The pictures of the dinosaurs’ dandruff, captured with a high-performance electronic microscope, depict extremely intact flakes, which are nearly similar to the flakes of modern-day birds. As human dandruff, the skin flakes are composed of thick cells named corneocytes, packed with keratin proteins.
The research, which appeared in the Nature Communications journal, hints that ancient feathered dinosaurs had previously progressed to deal with their feathering in the middle Jurassic. While they are in the very first phases of feather evolution, these dinosaurs have adjusted their skin to a more up-to-date structure, added Maria McNamara.
The fossilized dandruff remnants of all the samples examined were excavated from rock structures in northeastern China.
Modern-day birds also present very greasy corneocyte cells stuffed with keratin, a property that helps them lose heat through flying.
The skin cells of these ancient feathered dinosaurs, in contrast, were deficient in fats, indicating that they may not have been as warm as the modern-day birds, maybe due to the fact that they were not capable of flying much longer, or not at all.