The images of dinosaurs we can see today are all made by paleontologists through observation and research on dinosaur fossils and reasonable speculations. What are the true features of these giant beasts that have disappeared for 65 million years? At present, there is no 100% accurate conclusion in academia. However, with the deepening of scientific research, in recent years, paleontologists have discovered that many theropoda dinosaurs (Theropoda), which were originally thought to be covered with smooth scales, actually have feathers similar to modern birds. Found that they are similar to birds more than feathers!
Researchers have found that from sparrows to geese, from owls to ostriches, they have countless things in common with velociraptors or powerful tyrannosaurus. From the appearance, the two-legged theropod dinosaurs such as birds and velociraptors, tyrannosaurus, etc. stand on only two hind legs, and they all have feathers; from the perspective of reproductive methods, they all lay eggs.
In the eyes of the researchers, all modern birds originate from theropod dinosaurs. They are not only direct descendants of theropod dinosaurs, they are even living dinosaurs themselves.
Theropod dinosaurs first appeared 231 million years ago, and the earliest bird on the earth, the archaeopteryx, was born 150 million years ago. They have evolved their flying ability, and they are different from other theropod dinosaurs. Therefore, paleontologists often call all dinosaurs except birds-non-bird dinosaurs.
Today, all non-bird dinosaurs are extinct, but the birds have survived and grown as the only living dinosaur branch!
“Birds belong to dinosaurs, they are living dinosaurs, just as we belong to mammals!” said Julia Clark, a paleontologist who studies flight evolution and a professor of geology at the University of Texas at Austin. Just as there are differences in the physiological structure of various members of mammals, but every species in this large family—whether existing or extinct—has a common ancestor, and scientists can learn from this common Mammal ancestors found the same anatomical characteristics as all mammals, as did birds and theropod dinosaurs.
“They are firmly embedded in that part of the dinosaur family tree,” Julia Clark said. “All birds today are descendants of theropod dinosaurs.”
Modern birds have feathers on their tails and bodies, shoulder bones do not merge, beaks have no teeth, and their forelimbs are much longer than their hindlimbs. There is a bone plate near the tail-the tail bone, this triangular bone at the end of the spine plays a role in supporting the tail feathers. Takuya Imai, an assistant professor at the Institute of Dinosaurs at Fukui Prefecture University in Japan, said that the long-extinct theropod dinosaurs often possess one or more of these characteristics, and modern birds possess all of these characteristics.
In a study published in the Journal of Biology and Biology in November 2019, Takuya Imai described a 120 million years old primitive bird discovered in Japan. The researchers named it “Fukuipteryx prima”. It means “the wings of the original Fukui”. This is the earliest known bird with caudal hemibones. The structure preserved in the fossils is very similar to that of modern chickens. This means that some structures of modern birds can be traced back to their earliest ancestors.
However, palaeontologist Zou Jingmei of the Institute of Paleontology and Paleontology of the Chinese Academy of Sciences said that primitive birds and non-bird theropod dinosaurs still have a lot in common. Zou Jingmei pointed out that these animals have long, reptile tails, teeth in their mouths, and claws on their wings. In addition, many non-bird theropod dinosaurs have real feathers. These feathers have a feather axis, and the hooks on each side of the feather branch have small hooks. This fully shows that primitive birds and non-bird theropod dinosaurs have many common characteristics.
The first bird
Archaeopteryx (Archaeopteryx) was widely regarded as the earliest and most primitive bird for a long time, living 150 million years ago. This animal weighs about 1 kg and is about 50 cm long. Fossil evidence shows that its tail and body are covered with feathers. The shape of the forelimbs and feathers indicates that the archaeopteryx has the ability to fly, which is a characteristic of most modern birds. However, archaeopteryx has many different characteristics from modern birds, such as the claws at the tips of their wings.
However, the archaeopteryx has been shaken in the evolutionary history of birds with the discovery of fossils such as the near-bird dragon, Xiaoting dragon and dawn bird that are older than archaeopteryx and structurally closer to the living bird.
Zou Jingmei said that a distinctive feature of birds is their ability to fly, their large forelimbs are covered with asymmetrically shaped feathers, and strong muscles.
So, what is the evolutionary relationship between these primitive birds and theropod dinosaurs?
Zou Jingmei believes that the most primitive birds are likely to belong to the dinosaur subject that is the most similar to birds-one of the dinosaurs family, this dinosaur has evolved its flying ability, and since then they have been the same family Other relatives have made a clear difference and are unique in their development and growth. After the emergence of this evolutionary node, theropod dinosaurs were divided into birds and non-bird theropods.
“After the flight ability evolved, the small bones of the bird’s forelegs gradually shrunk and merged together to form a reinforced structure that supports the wings and feathers,” said Julia Clark. She pointed out that at the end of the Cretaceous period, after the extinction of non-bird dinosaurs, birds continued to evolve and became more and more diverse, developing more unique characteristics related to flight, such as the slender structure of the sternum (keel), And a powerful pectoral muscle that can power flapping wings.
Clark said that there are about 10,000 species of birds in the world today, as small as hummingbirds and as large as ostriches; there are both eagles that spread their wings and penguins that swim in the ocean. However, they are still in the same family as the theropod dinosaurs that hatched primitive birds 150 million years ago.
If you want to know exactly how the real dinosaurs walk, don’t go to the museum to ponder over the cold fossils, it’s better to pay attention to the red-billed gull that grabs snacks by the lake, or the white chasing children in the countryside. Goose! Yes, they will show you the real walking posture of dinosaurs, because they are dinosaurs!