the Paleontologists They have identified a missing link in the evolution of dinosaur feathers. A recent study published May 21 in the journal Nature Communicationsreveals that Some feathered dinosaurs also had scaly skin similar to that of modern reptiles.
the studycarried out by a team of University College Cork In Ireland and Nanjing University in China, I focused on a rare specimen of fossilized skin from a feathered dinosaur known as Psittacosaurus. This small, horned, bipedal dinosaur lived in modern Mongolia and China during the Early Cretaceous period, about 135-120 million years ago. Maria McNamara“The evolution of feathers from reptile scales is one of the most profound and least understood events in vertebrate evolution,” said study co-author and a paleontologist at University College Cork.
Use the team UV light To identify patches of preserved skin on Psittacosaurus, invisible in natural light. More detailed X-ray and infrared examination allowed us to observe Cellular structures Saved. Zixiao Yang“The fossil is truly a hidden gem,” said study co-author and a paleontologist at University College Cork. Only under UV light is the skin visibleWith an orange-yellow glow.”
One of the most important findings of the study is the chemistry of fossilized skin, which is composed of… SilicaIt is the same compound as glass. “This type of preservation has never been found before in vertebrate fossils. There may be many hidden soft tissue fossils waiting to be discovered“he added Yang.
These discoveries provide new perspectives on… Evolutionary transition from scales to feathers. According to the researchers, feathers likely evolved in specific areas of the dinosaur’s body, while other parts of the body retained scaly skin. This zonal development allowed the preservation of the basic functions of the skin, e.g protection Against corrosion, dryness and parasites.
Feathers have multiple uses in the animal kingdom. Not only does it facilitate flying, it also plays a role in it Attractive coupleas in the case of peacock. in PenguinsFeathers reduce drag when swimming underwater. In addition, the heron uses it to create shaped shadow “umbrella”. Most feathered dinosaurs belong to groups Theropods And the SauropodsWho probably used feathers for insulation and heat preservation.
Feathers evolved from Reptile scales It is still a topic of great interest among scholars. “Although many feather fossils have been studied, skin fossils are much rarer,” McNamara noted. This particular finding suggests that smooth skin, much like that of birds, may have initially evolved only in feathered areas of the dinosaur’s body, a phenomenon known as zonal evolution.
The Psittacosaurus fossil is currently at Nanjing University, and scientists hope future discoveries will make it Fossils with preserved soft tissue It could provide more information about the remarkable transition from scales to feathers. “It is possible that the first dinosaur to experiment with feathers survived and passed on feather genes to its descendants.” McNamara concluded his speech.
the Bird feathersthe Reptile scales And Mammal hair They share a common evolutionary origin. This is what a team of Swiss biologists revealed in an article published in the specialized magazine Advancement of science In June 2016.
According to researchers from University of GenevaThese three skin structures, known as phaneras, are derived from a common reptile ancestor. “This suggests that the three types of ghosts are homologous: despite their very different final appearance, reptilian scales, bird feathers and mammalian hair evolved from a common reptile ancestor,” he said. Michelle Milinkovic Follower University of Geneva.
Scientists have not yet reached this conclusion Examining the embryos of crocodiles, snakes and various types of pogonaA genus of reptiles. In their study, the researchers identified new molecular properties similar to those observed in the development of hair and feathers in mammals and birds. “During their studies, they identified new molecular properties similar to those seen in the development of hair and feathers,” according to the scientific details published by Advancement of science.
Until that moment, Plaques, the thickening of the epidermis that gives rise to these structures, were thought to be an exclusive feature of mammals and birds. However, in 2015, researchers from Yale University They discovered that scales, hair and feathers have the same molecular properties as they grow. This result was an important step in understanding the evolution of these structures, but questions remain. “The scales of reptiles, the hair of mammals and the feathers of birds have the same molecular properties as they grow.”This has been documented previously.
New studies conducted in Swiss They discovered that reptiles also possess these plates, suggesting a common evolutionary origin dating back to reptile ancestors. “Our study not only provides new data In continuation of the work of the American team“It also highlights important microanatomical conditions,” Milenkovic noted. These precise anatomical conditions provide a better understanding of how these structures develop in different animal lines.
Swiss research was accurate in its analysis of embryos. Biologists have examined both species CrocodilesWhich represent archosaurs such as Snakes and PogonaWhich represent lepidosaurs. All of these animals showed the same plaques previously identified in mammals and birds. “Reptiles have the same plates as mammals and birds,” Milenkovic said. This result demonstrates that these structures did not evolve independently in each line of animals, as previously thought, but rather They have a common origin.
The implications of this study are important for evolutionary biology. They shed new light on the evolution of vaniers and provide a better understanding of the evolution of surface traits in three very different groups of vertebrates. Careful molecular and anatomical analysis confirmed that Reptiles, Mammals And the birds They are not as different in their forms of early development as previously thought. “Our study suggests that all of these structures have a common evolutionary origin in reptiles,” Milenkovic said.
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