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Fossils dating back 160 million years reveal secrets on the flight
Researchers have discovered that a fossilized relic of the "four-winged" dinosaur, lived 160 million years ago, could shed new light on the flight's evolution.
"Anchiornis", which is about the size of a species of phylogeny, China 10 million years ago before the first known bird, "Archeopteryx", according to the website "Russia Today".
The chemical badysis revealed that the preserved feathers contained the same proteins as in birds today. Although they are not suitable for long-range flight, their molecular structure may indicate an intermediate step in the evolution of bird feathers.
Modern bird feathers consist of a protein called β-keratin, which gives it special biochemical properties, such as flexibility and strength, to meet the need for flying.
The anchiornis are characterized by the presence of α-keratins rather than by mild β-keratins.
"Modern bird feathers are mainly made up of β-keratin, a protein also found in the skin, claws and reptiles of birds and reptiles," said Professor Mary Schweitzer, a biologist at the University of California. University of North Carolina.
Feathers differ from other keratin-containing tissues because the feather protein undergoes modifications that make it more flexible. "
Mary explained that at some point during the development of the feathers, one of the "β-keratin" genes had undergone a simple modification, making the resulting protein slightly smaller.
This has changed the biophysics of feathers into a more flexible system, indispensable for aviation.
"If we can determine when and in what organisms this explosion took place, we will be able to better understand the evolution of aviation as we move from dinosaurs to birds," she said.
His international team was able to demonstrate how the feathers of Jurisaurus dinosaurs differed at the molecular level from those of younger fossil birds and modern counterpart birds.
The study leader, Yan Hong-Ban, paleontologist at the Nanjing Institute in China, studied the fossilized feathers of Anchiornis, using high-resolution scanning techniques, to determine its composition.
The same process was repeated with medieval feathers and the age of "Cenozoic", in addition to other tissues of keratin that were not supposed to show the presence of this mutation, and then scientists compared the results with samples of feathers and chicken tissue.
Feather fossils have greatly improved our understanding of their evolutionary badociation with birds, as well as the origins of flight, said Dr. Ban.
In live birds, determine the unique expression and composition of amino acids proteins present in mature feathers, as well as their biological properties, such as hardness, elasticity and plasticity.
"We provide here molecular evidence that the feathers of Anchiornis dinosaurs, consisting of (β-keratins) and (α-keratins), are important because mature feathers in live birds controlled by (β-keratins).
The researchers also confirmed that the feathers had been modified at the molecular and morphological levels in order to obtain the biochemical properties of aviation during the transition between dinosaurs.
The study, published in the Proceedings of the National Academy of Sciences, revealed that Anchiornis is composed of beta-alpha-keratins, a protein that all terrestrial vertebrates, including mammals, possess.
This was surprising because "α-keratin" only exists in small amounts in modern feathers.
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