Strong yet light, elegant and precisely structured, the feather is essentially the most complex skin appendage ever to evolve in vertebrates. Despite this fact, man has been fidgeting with wings. Since prehistoric timesthere's still lots we don't understand about them.
our A new study It seems that among the first animals with wings had rough skin like reptiles.
After the introduction of the primary feathered dinosaurs, i 1996the addition of discoveries has painted a fair more interesting picture of the evolution of feathers.
We now know that many dinosaurs and their flying cousins, the pterosaurs, had wings. Feathers got here in lots of forms prior to now – for instance, Feathers like ribbons Extended suggestions were present in dinosaurs and extinct birds, but not in modern birds. Birds today have inherited only just a few primitive feather types.
Biologists have also learned that primitive birds weren't designed for feathers. Flight. Early feather fossils had easy structures and sparse distribution on the body, in order that they can have been for display or tactile sensing. Pterosaur fossils suggest they could have played one. Role in thermoregulation and I Color patterning.
As interesting as these fossils are, ancient plumage tells only a part of the story of feather evolution. The remainder of the motion took place soon.
Today the skin of birds is soft and developed. for supportControl, growth and coloration of feathers in contrast to the rough skin of reptiles.
Fossils of Dinosaur skin are more common than you think that. However, thus far, only a handful of dinosaur skin fossils have been examined on the microscopic level. These studiesFor example, a 2018 study of 4 fossils with preserved skin showed that the skin of early birds and their close relatives ( Coelurosaurs) was already just like the skin of birds today. Bird-like skin evolved before bird-like dinosaurs got here around.
So to know how bird-like skin evolved, we want to review the dinosaurs that form the primary branches within the evolutionary tree.
Our study shows that no less than some feathered dinosaurs had rough skin, just like that of reptiles today. The evidence comes from a brand new specimen, accompanied by a horned dinosaur. Like Brussels feathers on its tail. lived within the early Cretaceous period (about 130 million years ago), but his tribe, Ornithischian dinosaursIn the Triassic period (about 240 million years ago) they diverged long before the opposite dinosaurs.
In the brand new model, the soft tissue is hidden within the naked eye. Under ultraviolet light, nonetheless, rough skin reveals itself as an orange-yellow glow. Skin is preserved on the torso and limbs, that are parts of the body that didn't have wings.
These vivid colours are from the silica mineral that's answerable for preserving the fossil's skin. During fossilization, silica-rich fluids seep into the skin before it decomposes, replicating the feel of the skin in incredible detail. Fine anatomical features are preserved, including the epidermis, skin cells and skin pigments called melanosomes.
Fossil skin cells have lots in common with modern reptile skin cells. They share the same cell size and shape and each have fused cell boundaries – a feature known only in modern reptiles.
The distribution of fossil skin pigments is comparable to that of contemporary crocodile scales. Fossil skin, nonetheless, appears to be relatively thin by reptilian standards. This suggests that fossil scales were just like reptile scales.
Provided by Zixiao Yang/writer
Reptile scales are hard and hard because they're wealthy in a form of skin-forming protein, tough. Corneal beta protein. In contrast, the soft skin of birds is made from a special form of protein, keratins, that are key structural materials in hair, nails, claws, hooves and the outer layer of our skin.
To provide physical protection, the skinny, bare skin should be composed of tough reptilian-style corneous beta-protein. A bird's soft skin would have been too fragile without feathers for defense.
Collectively, the brand new fossil evidence suggests that reptile-style skin existed in areas where it lacked feathers. The tail, which in some preserves the feathers. Samplesunfortunately no feathers or skin are preserved in our specimen.
However, the tail feathers on the opposite Samples show that some features of the bird's skin can have already evolved to carry the feathers in place. So our findings suggest that early feathered animals had a combination of skin types, with bird-like skin only on the winged areas of the body, and the remaining still having rough skin, like modern reptiles. in animals.
The development of this zone ensures that the skin protects the animal from scratches, dehydration and pathogens.
What next?
The next knowledge gap for scientists to explore is the evolutionary transition from reptile-style skin to the skin of other more heavily feathered dinosaurs and early birds.
We also need more experiments to review the strategy of fossilization itself. We don't understand much about how soft tissue fossils are formed, which implies it's hard to inform which skin features in a fossil are true biological features and that are just artifacts of fossilization.
Over the past 30 years, the fossil record has baffled scientists. Wing evolution. Future discoveries of fossilized wings may help us understand how dinosaurs and their relatives developed flight, warm-blooded metabolism, and the way they communicated with one another.