The earliest bird fossils in China: The newly discovered bird fossils in the world were collected from the dark gray-gray black thin tuffaceous silty mudstone of the late Mesozoic Qiaotou Formation in Longfengshan, Fengning, Hebei, China. China golden phoenix Bird, which is older than Archaeopteryx.
Scientists analyzed the complete archaeopteryx fossils and found that the feet of archaeopteryx were similar to those of theropod dinosaurs. This discovery provides new support for the theory that birds originated from dinosaurs.
About 160 years later, dinosaurs were first discovered by humans. The earliest discovery was a big bone. Because people knew little about biological evolution at that time, it was described as a leg bone fossil of an ancient great ape. From this fossil, people began to find many other dinosaur fossils. Archaeopteryx is the oldest known bird ancestor. /kloc-in the middle and late 9th century, scientists first discovered archaeopteryx fossils living about1500,000 years ago in limestone beds in Bavaria, Germany. In recent years, more archaeopteryx fossils have been unearthed by paleontologists in China and other countries, which partly proves that archaeopteryx has the closest genetic relationship with carnivorous theropods, and supports the theory that birds originated from dinosaurs.
There are two hypotheses about the dinosaur origin of birds. One is the terrestrial theory, that is, the dinosaur first ran on the ground, and then it ran and flew into the sky. Another hypothesis is arboreal theory, that is, when the dinosaur first climbed a tree and then lived among trees, for example, when it jumped from one tree to another, or when it jumped from a tree to the ground, it had a landing process, during which it became gliding, and then in this slow process, it learned to fly. Now many paleontologists support the arboreal theory based on fossil research.
Meyer of the Senkenberg Museum of Natural History in Frankfurt, Germany, and Pearl of the Wyoming Dinosaur Center in the United States reported in the new issue of Science that the archaeopteryx fossil they analyzed is the best preserved one so far. This fossil contains almost complete archaeopteryx bones, especially its foot bones are very clear. This fossil was found in the limestone layer near Thornhoven, Bavaria, Germany, where the archaeopteryx was first discovered by scientists and is currently preserved in the Wyoming Dinosaur Center. Fossils show that this archaeopteryx lived in the late Jurassic about1.500 million years ago, and was the size of a modern magpie.
Meyer and others found that the foot of this archaeopteryx was very different from that of modern birds and closer to that of theropod dinosaurs. The most obvious feature is that its second toe can be overstretched, almost the same as the feet of dinosaurs such as Microraptor and Bird's Foot Dragon. In addition, the first toe of this archaeopteryx grows inward, not extending outward like the toes of birds, but somewhat similar to the thumb of a human palm; Moreover, its jawbone grows radially in all directions, which has obvious genetic characteristics of theropod dinosaurs. Scientists say that this fossil not only shows that birds originated from theropods, but also shows that Archaeopteryx didn't climb the toes of branches like modern birds, so it didn't live on branches. Archaeopteryx is not so much a bird as a theropod dinosaur such as Raptor and Deinonychus.
This discovery may lead to a new debate about the boundary between dinosaurs and birds. Meyer and others said that from the fossils of archaeopteryx, if archaeopteryx and modern birds are counted as birds, then this big family should include some deinonychus. Because some deinonychus have wings and feathers, they have "real bird characteristics".
The mystery of bird ancestors
In the past, people always thought that birds originally evolved from reptiles. Archaeopteryx is the product of the intermediate stage of this evolutionary process. It has always been considered as the ancestor of birds. Although this evolutionary theory seems to have some truth, many paleontologists still have some doubts about the conclusion that reptiles like lizards will really become birds because of mutation and natural selection. As a result, in academic circles, experts have launched a protracted debate on the issue of birds.
In the era when Darwin's Origin of Species was just published, people could not understand the view that birds first evolved from reptiles. Later, in 186 1 year, archaeologists discovered a strange biological fossil in a limestone quarry in Germany. This fossil has wings, teeth in the mouth, claws in the front of the wings, and a long tail composed of multiple coccygeal vertebrae like a lizard. The discovery of this fossil called Archaeopteryx excited many archaeologists and paleontologists. Because many people insist that "birds evolved from lizards", here is the basis. However, today, this widely accepted view suddenly loses its authority. Because in 1986, American archaeologists discovered bird fossils 75 million years earlier than Archaeopteryx in Texas. And named it "primitive bird", then the "throne" of bird ancestors will be taken away by primitive birds. Paleontologists point out that if so, the idea that birds evolved from reptiles will also be denied.
Regarding the origin of Archaeopteryx, Pomfret of the British Museum pointed out that in the past, people thought it was a reptile group that was the ancestor of birds, but it was not actually a lizard. Archaeopteryx evolved from a member of dinosaur family. Archaeopteryx and dinosaur are both "distant relatives" and "close neighbors", and both originated from teeth. Undeniably, Archaeopteryx and a small dinosaur called Bone Dragon do have very similar skeletons, so as early as the last century, paleontologists believed that the ancestors of birds were dinosaurs of this group.
From the appearance, many birds are very similar to dinosaurs now. Among dinosaurs, there was a parrot-billed dragon, whose mouth was very similar to that of a parrot that taught everyone to talk. The feet of ostrich dragons are the same as those of ostriches. He also has three toes and is good at walking. Ostrich dragon had no teeth, and neither did ostrich. A hadrosaur's mouth is like a duck's mouth, and a hadrosaur swims like a duck. Birds have hair, and Lianlong, who lived 65.438+0.8 billion years ago, has long hair all over his body. Birds have hollow bones, so that they can lose weight and fly easily. The bones of some early dinosaurs were also hollow. Scientists believe that among these dinosaurs, Bonosaurus is light and agile, and its shape and body structure are very similar to those of birds.
In the process of exploring the origin of birds, one of the focuses of debate is the clavicle problem. The left and right clavicles of birds adhere to each other, which is a V-shaped healing clavicle and is very developed. The dinosaur's collarbone completely disappeared because of degeneration. In this regard, people who hold the view that "birds originated from dinosaurs" think that both dinosaurs and birds originated from teeth, but the clavicle changed differently in the later evolution, so it cannot be said that dinosaurs were not the ancestors of birds. However, when putting forward the above viewpoint, some scientists found some boneless dinosaurs with collarbones. Through fossil analysis, it is found that the bones of Archaeopteryx and Boneless Dinosaur are obviously similar, but many of them have characteristics that teeth do not have. This overturns the previous view that dinosaurs and birds originated from teeth.
Later, the fossils of primitive birds were discovered, and experts and scholars with different views turned their attention to primitive birds, trying to find a new theoretical breakthrough from primitive birds. After analyzing the fossils of primitive birds, paleontologists were surprised to find that primitive birds had many characteristics closer to birds than archaeopteryx.
Some scientists believe that the origin time of birds should be explored before primitive birds. The discovery of primitive birds is likely to deny the previous view that birds originated from dinosaurs. The discovery of primitive bird fossils undoubtedly provides new information for exploring the origin of birds, but scientists have not yet reached an agreement on who the ancestors of birds were, and can only draw a conclusion after discovering older bird fossils.
China found the most primitive bird fossils in the world.
The reporter recently learned from the Chinese Academy of Geological Sciences that the research team headed by researcher Ji Qiang of the Chinese Academy of Geological Sciences recently discovered the world's most primitive bird fossils for the first time in the late Mesozoic strata in Fengning, Hebei Province, and the researchers have officially named it Huamei golden phoenix. The preliminary research results of this new discovery have been published in the Geological Bulletin published in March this year, which indicates that the research on the origin of birds in China has made great progress again and is at the international leading level.
Ji Qiang said that the newly discovered bird fossils are the most primitive in the world. They were collected from the dark gray-gray-black thin tuffaceous silty mudstone of the late Mesozoic Qiaotou Formation in Longfengshan, Fengning, Hebei Province, China, and their * * * organisms are common molecules in the Jehol biota, such as wolf fin fish Dai, sturgeon Pan Beipiao and some plants.
According to 205 features, Ji Qiang and others made a branching analysis of golden phoenix. The results show that golden phoenix is at the base of the early bird pedigree tree, slightly more primitive than Archaeopteryx, and has a sister group relationship with the latter. Long Ben, Egg Stealing Dragon and other theropod dinosaurs are the outer groups of golden phoenix and Archaeopteryx, and also the outer groups of primitive birds such as China Shenzhou Bird, indicating that golden phoenix is in a very key position in the evolution from dinosaurs to birds, and is the most primitive early bird found in the world so far.
Ji Qiang said that although golden phoenix is closely related to Archaeopteryx and is a sister group, relatively speaking, golden phoenix is more primitive than Archaeopteryx in some features. According to the results of cladistic analysis, the first bird in the world should be golden phoenix in China, not the German archaeopteryx.