September 10
"People's Daily Overseas Edition" published an article on page 7
Chengjiang Fossil Land World Natural Heritage Museum
Telling the story of the evolution of life on Earth》
Take us back to the origins of biology
Feel the colorful life
In Chengjiang, Yunnan Province, there is a unique world natural heritage - Chengjiang Fossil Land. A large number of Cambrian fossils preserved here witnessed the Cambrian explosion of life 518 million years ago, so the Chengjiang fossil site is praised by the international scientific community as a "world-class fossil treasure house".
Chengjiang Fossil Land World Natural Heritage Museum (data map)
The Chengjiang Fossil Land World Natural Heritage Museum (Yunnan Provincial Museum of Natural History) is located on Cambrian Avenue on Huanhu North Road in Chengjiang City, and is the only natural history museum built on a fossil site in China. Its architectural design is very unique, with the appearance of a giant cradle, alluding to the origin of life. The museum has a construction area of 42,000 square meters, in addition to the exhibition space, there is a visitor center, a dome theater, a scientific research center, a research center, etc., is a collection of collection, research, display, education as one of the large-scale natural museum. The museum has a collection of more than 60,000 fossils and specimens, including 50,000 biological fossils in Chengjiang and more than 10,000 fossils and living animal specimens from other geological periods.
Chengjiang Fossil Land World Natural Heritage Museum. Source: Yunnan Provincial Museum of Natural History
Tracing the origins of living things
Walking into the museum's prologue hall, you will be greeted by the spiral-shaped "Life Evolution Tree" art installation in the center of the dome, each branch representing a type of creature.
Guo Jin, deputy director of the Chengjiang Fossil Land World Natural Heritage Museum, said that the earth's 4.6 billion years of history is mainly divided into two stages: the Cryptozoic and the Phanerozoic, and the Cambrian period, which is about 541 million to 485 million years ago, is the watershed of the two stages. Before the Cambrian period, life forms on Earth were extremely monotonous. Since the Cambrian period, various organisms have emerged in large numbers, and scientists call the Cambrian "explosion of life". The Cambrian fossils found in the Chengjiang fossil field so far belong to more than 20 categories and more than 300 species, and the ancestors of almost all living animal phyla can be found here, which can be said to be the root vein of the "tree of life evolution".
Underneath the "Tree of Life Evolution" stands a tall wall of fossils. "This is the real stratum where the Chengjiang fossils are buried, and it records the life scenes of Cambrian creatures." Commentator Cao Ruyi introduced, "More than 500 million years ago, the land under our feet was still a vast ocean, where ancient creatures roamed and thrived freely. A geological disaster struck, and these creatures were buried in the sediment and formed fossils over a long period of time. ”
Chengjiang Biota Fossil Repository. Source: Chengjiang Rong Media Center
Guo Jin introduced that the basic exhibition of the museum is divided into three parts: "The Great Explosion of Life", "The Great Evolution of Life" and "Biodiversity", with a total of more than 4,700 exhibits.
In the exhibition hall of "Fossil Holy Land", the scene of Hou Xianguang's initial discovery of Chengjiang fossils is restored. In 1984, Hou Xianguang, a researcher at the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, came to Chengjiang to carry out field investigations. On July 1, he braved the rain to climb Maotian Mountain. After knocking on many stones, a lifelike fossil of the Naro worm appeared in front of him, and Hou Xianguang was excited, this kind of fossil had never been found in the formation before. As the research work continues, more and more Cambrian fossils have been discovered. In 1987, the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, held a press conference to release the discovery and research results of Chengjiang biota to the world.
The discovery of the Chengjiang biota fills the gap in the evolution of the two paleontological groups of Ediacara and Burgess, and provides important data for the study of the Cambrian explosion of life. Over the years, a large number of research results on Chengjiang biota have been published in important international academic journals such as Nature and Science. Scientific research projects such as "Chengjiang Fauna and Cambrian Explosion" have won the first and second prizes of the "National Natural Science Award". In 2012, the Chengjiang Fossil Site was inscribed on the World Heritage List, becoming the only fossil world natural heritage site in Asia.
Cambrian "undersea tunnel" scene. Photo by Chen Xinbo
Entering an "undersea tunnel" made of OLED flexible screens, the early Cambrian marine ecosystem is vividly presented in front of you. High-definition digital technology reproduces more than 200 species of Cambrian creatures, such as sponges and sea anemones that inhabit the seabed, Kunming fish and jellyfish that swim in the water, and the majestic predator shrimp......
In the unit of "Distant Ancestors of Human Beings - The First Fish in the World", the "treasure of the museum" - Fengjiao Kunming fish fossils are displayed. Humans belong to vertebrates, and the Kunming fish in the Chengjiang biota is the oldest known vertebrate and is regarded as the common ancestor of vertebrates. The Kunming fish is only about 3 centimeters long, but it has evolved the basic body structure and organs of vertebrates, such as brains, eyes, hearts, etc., and Shu Degan, a paleontologist and academician of the Chinese Academy of Sciences, called it "the first step in the long evolutionary process towards the future of intelligent humans". The video on the screen shows scientists reconstructing the image of the Kunming fish, with a pair of eyes and five pairs of gill sacs on its head, and a dichotomous heart between the gill area and the intestine. The fossil specimen of Kunming fish is particularly rare, and this Kunming fish fossil in the museum's collection has high research value.
Fengjiao Kunming fish fossil. Photo by Chen Xinbo
Rare fossils on display
The Chengjiang biota is rich in species, covering almost all phyla of living animals, such as porous animals, coelenterates, nematoids, phylopods, brachiopods, molluscs, arthropods, echinoderms, chordates, etc.
Porous animals, also known as sponges, are the most primitive and lowest-grade aquatic multicellular animals, and there are about 10,000 species of sponges known at present. The exhibition hall displays the sponge fossils found in Chengjiang, which contrasts with the living sponge breeding scene. According to reports, the sponge is fixed on the seabed, feeds on decaying organic matter, bacteria, algae and biological larvae, and can also absorb amino acids dissolved in water, which has the effect of purifying the ocean, and is called the "water purification factory" on the seabed.
Coelenterates occupy an important position in the history of evolution, with primitive digestive cavities and primitive nervous systems. The Chinese Xianguang anemone is one of the most primitive coelenterates and is named after Hou Xianguang, the discoverer of the Chengjiang biota. The anemone is cylindrical and consists of a base plate, a mouth plate, and 16-18 tentacles. Unlike offspring anemones, which hunt with stinging cells, it filters food with elongated cilia.
Leaf pods were the first animals on Earth to walk on their legs. The preserved Chinese microreticulum was first found in the Chengjiang biota, with an elongated body with a short head and a long tail, with 9 pairs of reticulated bony plates and 10 pairs of clawed leaf legs on the trunk. Early scientists believed that these bone plates had a light-sensitive effect, possibly its eyes, hence its nickname "nine-eyed elf".
Fossilized large scratch of the odd shrimp. (Photo courtesy of Chengjiang Fossil Land World Natural Heritage Museum)
Shrimp is the "giant" of the Cambrian ocean, located at the very top of the food chain. "Why is it called a prawn? Because at first scientists only found its large grapples, shaped like segmented shrimps, without a head, which is very strange. Cao Ruyi introduced that the strange shrimp is huge, up to more than 2 meters long, and complete fossils are very rare. In addition to the large grasping limbs, the torso of this fossilized shrimp in the display case is also intact, with a length of 70 centimeters from head to tail.
The animation on the screen demonstrates the scene of the odd shrimp swimming and hunting. The shrimp has a streamlined body with multiple pairs of fins and is good at swimming. There is a pair of compound eyes with handles on the head, which is composed of tens of thousands of single eyes, which can rotate 360 degrees and has a strong visual function. Most notable are the large grappling limbs in front of its head for catching prey, and its mouth has a ring-like arrangement of teeth that allow it to hunt larger creatures.
Extension of Fuxian Lake insect fossils. (Photo courtesy of Chengjiang Fossil Land World Natural Heritage Museum)
Arthropods are the largest family in the animal kingdom, with more than 1.12 million species of living arthropods named, accounting for more than 80% of the total number of living animals. Fuxian Lake insect is the primitive ancestor of arthropods, the adult body length is more than 10 centimeters, there are 31 segments, divided into three parts: head, thorax and abdomen. Scientists discovered the circulatory system and nervous system of Fuxian Lake worm, opening up a new field of paleontological research - paleontology. In addition, it was also found that Fuxian Lake insects would live with their larvae, which may have had the earliest family concept. The mascots of Chengjiang Fossil Land, "Qiqi" and "Yuanyuan", are designed according to the image of Fuxian Lake insects.
Yunnan insect fossil specimens are often lead-colored, so the scientific name is lead-colored Yunnan insect. Some paleontologists believe that Yunnan worms have a tubular notochord and may be the earliest chordates. The United States "New York Times" once commented, "If the Yunnan worm dies, the central nervous system of animals will never develop, and the earth will be as lonely and lonely as the distant moon."
Feel the colorful life
From the post-Cambrian Ordovician to the Cretaceous, the earth has experienced five mass extinctions. After entering the Cenozoic Era, primate mammals began to emerge and gradually evolved into humans. The museum displays representative biological fossils from various geological periods, outlining the magnificent evolution of life on earth.
Source: Chengjiang Rong Media Center
The Jurassic period, which dates from about 201 million to 145 million years ago, is known as the "Age of Dinosaurs", a period when the variety and number of dinosaurs increased unprecedentedly, and gymnosperms flourished. In 1938, paleontologist Yang Zhongjian excavated China's first complete dinosaur skeleton fossil in Lufeng, Yunnan Province. In the exhibition hall, you can see the fossil of Lufengsaurus, as well as its close relative, Yunnan dragon. This Yunnan dragon fossil was excavated in Tiantou Mountain, Chengjiang City in 2018, and the preservation integrity is 60%. Its skull is long and small, and its teeth suggest that it belonged to a herbivorous dinosaur.
The first dinosaur to evolve feathers - Nearornithosaurus het, the apex predator in the Cretaceous ocean - Canglong, the mammal that lived in the ocean 40 million years ago - the dragon king whale, the largest known terrestrial mammal - the giant rhinoceros, and the representative of the "Hezheng mammal fauna" in the Neogene - Samorin, three-toed horse, ancestral deer......
In addition to a wide variety of fossils of ancient creatures, the museum also displays representative living animal specimens of Yunnan. The Yunnan golden snub-nosed monkey is a national first-class protected animal, only distributed in the northwest of Yunnan, and is known as the animal that looks most like a human. The green peacock is the auspicious bird loved by the people of Yunnan, and the prototype of the "green chicken" of the legendary "Golden Horse and Biji" is the green peacock.
The "Biodiversity" gallery features more than 200 taxidermy specimens from Africa and North America donated by the Behring Foundation for Global Health and Education. The museum places these specimens in savannas, tropical rainforests, tundra, wastelands, temperate cold forests, wetlands, mountains and other ecological scenes, vividly presenting the beauty of biodiversity in nature.
After visiting the museum, it is like reading a magnificent epic of life. After an incomparably long and arduous evolutionary development, the colorful ecosystems on the earth today have been formed, and people can't help but admire the magic of nature and the preciousness of life.
(The author is a researcher at the Institute of South and Southeast Asian Studies, Kunming, China)
Source: People's Daily Overseas Edition, Yuxi Release
Editor: Jiang Lei
Review: Zhong Ling
Final review: Peng Deguang