The study of animal fossils in Pan'an, Guizhou Province, was re-transmitted. The palaeontologists in China discovered for the first time the fossils of the oldest bilaterally symmetrical animals that lived 580 million years ago. Today, "Science" magazine first officially announced this discovery to the world through the Internet as an express news. The long-awaited mystery was opened. On February 5, 1998, Chen Junyuan and Li Jiawei, together with Xiao Shuhai and Zhang Qiang, and the two teams respectively published 580 million in the United States in the magazines of Science and the United Kingdom. Years ago the discovery of multicellular animals and embryonic fossils. The Washington Post of the United States issued an exclusive comment on the same day, saying that this discovery "unexpectedly opened a window to a magical and critical historical period of life on Earth.... The new discovery opened a new way to find ancient animal fossil records, as if The heavy fog that was in sight suddenly disappeared...". This discovery was hailed by the international scientific community as "one of the most important scientific advancements in evolutionary biology in this century and will stir up waves in the scientific community...". Since then, Chinese scientists have carried out a series of researches on the animal fossils in Pan’an and obtained many important discoveries, including coelenterate adult fossils and embryo fossils, and possibly bilaterally symmetrical animal embryo fossils. These findings were discovered in 2000. Two times in the "American Academy of Sciences" and 2002 "Developmental Biology" magazine. However, whether or not animals with bilateral symmetry existed 580 million years ago, it is still the answer that the scientific community eagerly wants. This answer remains to be found in fossils. Work pays off. After nearly 6 years of hard work, researchers from the Nanjing Institute of Geology and Palaeontology at the Chinese Academy of Sciences, Professor Chen Junyuan and his colleagues at home and abroad, the mystery was finally revealed by the recently discovered 10 well-preserved fossils of bilateral symmetrical animals. This major discovery was recently Science magazine was published as a research paper. Before the magazine was printed, Science magazine first officially announced this discovery to the world through the Internet as an express news. The 10 well-preserved bilateral symmetry animal fossils of the happy life of the small springworms in Guizhou were found in the Luan phosphorus-containing section of the Precambrian Doushantuo Formation in Luan, Guizhou Province, about 580 million years ago. Chen Junyuan and other animal fossils stored in this phosphorus-containing layer are called Zhao'an animal fossils. Since the fossils of this kind of bilaterally-symmetrical animal are currently found to be small, only 0.2 millimeters, the time it has to survive is very special. This is equivalent to the fact that the harsh winter of our Earth "snowball event" has just passed and the early spring has just arrived. Chen Junyuan et al. named the ancient animal as a "spring worm" and dedicated the name of this oldest animal to the origin of this animal fossil - Guizhou, China. Although the individual animal is very small, it preserves a pair of bilateral symmetric structures such as body cavities and sensory fossa arranged in pairs. This animal is composed of ectoderm, endoderm and complete mesoderm. It is the fossil representative of the oldest known true cavity cavity symmetry animal. The front of the digestive tract of this animal has a mouth opening to the abdomen and a pharyngeal tract behind the tight junction. The pharyngeal tract is surrounded by a multi-layered pharyngeal wall. The complexity of this animal construct suggests that it is already in its adult stage of development. This discovery of fossils has for the first time pushed the history of reliable fossil records of bilaterally symmetrical animals to 40 million years before the Cambrian. The origin of the real body cavity animal is still a mystery of science. The discovery of this ancient animal cavity fossil will provide important clues for the exploration of the origin of true cavity animals. It shows that the true body cavity is likely to be an ancient feature of bilateral symmetry animals. Such a small animal has already begun to have the structure of the three germ layers. This phenomenon suggests that the time required for the developmental procedures necessary to form a three-sided symmetric animal may be earlier than the time for the formation of a large individual growth program. The complex body structure of the small spring worm also shows that the gene kits and the pattern formation mechanisms of bilaterally symmetrical animal development stages have been formed as early as 40 million years prior to the Cambrian period. Chen Junyuan and others believe that this ancient miniature animal mainly lives in the high-energy zone under the shallow water tide. Because this area is extremely active due to currents and waves, these animals, which are only 0.2 mm in size, are at risk of being swept away by currents and waves at any time. Therefore, this animal is similar to a group of existing microfauna and mainly hides in the gap between seafloor dust. Within it, it is not only possible to avoid harassment by currents and waves, but also to obtain the food and nutrients needed for survival, because the pores contain a large amount of soluble organic matter and organic debris that are released by biodegradation. The mouth of the animal is located in the front of the abdomen and has a well-developed pharyngeal tube immediately after the interface. It is inferred that this animal may be sucked out from the surroundings and dissolved or suspended in water by assisting the pharynx muscle through the mouth located in the abdomen. Organic nutrients in water. Chen Junyuan also believes that the way of hiding in the airspace of the cuttings and feeding by sucking is likely to be an ancient ecological way, while the herbivorous and burrowing ways take place later than the above ecological modes.
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