Fossil dandruff: yes, even the winged dinosaurs of 125 million years ago lost dandruff, so much so that it is found today, hidden in the plumage. It is the first scientific evidence on the "skin replacement" mechanism of these extinct animal species
He is about to end up run over, his mother saves himFossil dandruff: yes, even the winged dinosaurs of 125 million years ago lost dandruff, so much so that it is found today, hidden in the plumage. It is the first scientific evidence on the "skin replacement" mechanism of these extinct animal species.
A group of paleontologists from the University of Cork (Ireland), in collaboration with an international team from the United Kingdom and China, has discovered 125 million-year-old dandruff thanks to a comparative study between fossil cells and dandruff from modern birds and with the help of powerful electron microscopes.
Just like the dandruff of living beings, fossil dandruff is made up of hard cells called corneocytes, at the base of the skin renewal mechanism. During their journey towards the superficial layers of the epidermis, in fact, the said cells keratinocyte, gradually become loaded with keratin to become corneocytes and form the stratum corneum. The process ends with a flaking that generates dandruff and leaves room for new cells.
"The fossil cells were preserved with incredible detail, down to the level of nanometric keratin fibers - explains Maria McNamara, lead author of the study - It is incredible that fossil dandruff is almost identical to that of modern birds, and that even the spiral twisting of the individual fibers is still visible ”.
The study also suggests that this modern skin feature evolved in the Late Middle Jurassic, along with a number of other skin features. "There were a great many evolutions of feathered dinosaurs during that time, and it is exciting to show that their skin was evolving rapidly in response to the range and arrangement of the plumage."
Dandruff is in fact the first proof of how dinosaurs lost their skin (as indeed happens for us too). The feathered dinosaurs studied, Microraptor, Beipiaosaurus, and Sinornithosaurus, clearly lost their scaly skin, as did the Confuciusornis and similarly to other modern birds and mammals. In other words, dinosaurs did not shed skin like reptiles (whole), but in pieces.
Photo: University of Cork
However, while modern birds have very fatty corneocytes with "dilute" keratin, which allows them to quickly cool off when flying for long periods, the corneocytes of ancient species were instead filled with keratin, suggesting that these did not overheat as modern species do, probably because the birds did not fly at all or at least not for long periods at the time.
So even the winged dinosaurs lost dandruff, and therefore we now know that even in prehistoric times this phenomenon was observed. Will the images and animated reconstructions of winged dinosaurs flying undisturbed in the prehistoric sky have to be corrected with some bizarre rain?
The work was published in Nature Communications.
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Roberta de carolis
