Production: Feng Weimin (Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences)
Producer: Computer Network Information Center
Fossils are biological remains left over from ancient times and important evidence for paleontologists to explore the history of natural life. From the fossil excavation, we have learned a lot about animals and plants that have long since disappeared from the earth, such as dinosaurs, trilobites, graptolites, ammonites, coins, toothed beasts, ostriches, honeycomb corals, Chinese dragon birds, three-tailed ephemera, wolf-winged fish, three-toed horses, saber-toothed tigers, tongue-toothed sheep teeth, Kodak wood and so on. It is the choice of nature and biological evolution that has created their various peculiar biological forms and structures, such as giant dinosaurs, fish dragons who are good at swimming, all kinds of strange insects, trilobites resembling alien creatures, and exquisitely constructed ammonites.
△ Chrysanthemum Stone (Source: Wikipedia)
When it comes to the discovery of fossils, there may be a picture in everyone's mind: many experts shuttled between rocks with various professional equipment, and knock knock was pleasantly surprised to find fossils. In fact, not only experts, but also a group of people have become "fossil hunters" because of their love for fossils. So, what kind of person is a fossil hunter?
As early as 3000 or 4000 years ago, humans discovered fossils and had great interest and suspicion about them. Some people regard fossils as mysterious things, some people regard fossils as available drugs, and some wise people suggest that fossils are ancient creatures that can indicate environmental changes. Since ancient times, there have been many fossil lovers at home and abroad. They are full of incomparable interests and hobbies for fossils, and even devote their lives to the excavation and research of fossils. As a result, a proper term "fossil hunter" appeared, especially those enthusiasts and researchers who combine their interests and careers to dig and collect paleontological fossils.
This title appeared abroad as early as19th century, and mary anning was the most famous female fossil hunter in Britain in19th century. When she 10 was in her teens, she found a 5-meter-long and strange-looking marine animal fossil on the steep cliff along the coast of the English Channel. This is the first complete ichthyosaur fossil found in history.
Peace began her extraordinary life. In the next 35 years, she collected a large number of fossils, including two other important discoveries. 182 1 year, the first plesiosaur fossil was discovered in Marian. It took her 10 years to excavate this fossil. 1828, a bipedal fossil was discovered in Mary Anning, which is also considered as the first complete pterodactyl fossil. These discoveries became the key evidence of extinction, and now people can see these precious fossils in the Natural History Museum in London.
△ British mary anning Fossil Hunter (Source: Wikipedia)
Now with the popularization of fossil knowledge, more and more people are fascinated by fossils, and there are also collectors and appreciators among the people. So, what knowledge and necessary preparations do you need to be a qualified fossil hunter?
For most human beings, fossils seem to be very mysterious and rare treasures, which are collected in major museums. But in fact, fossils are not mysterious, even around us. As long as you have a pair of eyes that are good at discovery and the courage to explore and study, you can find traces of fossils in many places.
To be a good fossil hunter, the most important thing is to have basic knowledge of geology and paleontology, such as what fossils are, what types of fossils are, how to preserve them, what rock types to look for and so on. At the same time, we must have a certain aesthetic ability of fossils and feel from the heart that it is the evolutionary beauty of fossils that allows us to cross the imagination of life history and lead people into the free kingdom of mastering the true meaning of biological evolution.
In fact, fossils are often preserved in rocks of various geological ages in various forms, thus leaving countless traces in the history of the earth, and becoming good companions for us to understand the appearance of ancient creatures and trace back to the natural environment of the earth in ancient times. Fossil records can be traced back to 3.8 billion years ago and appeared in different geological ages. Therefore, fossils can witness the long evolutionary history of life on earth.
However, fossils do not exist in all rock types. Among the three kinds of rocks on the earth, namely metamorphic rocks, volcanic rocks and sedimentary rocks, volcanic rocks and metamorphic rocks have experienced high temperature and high pressure, so they cannot be preserved. Fossils can be widely preserved in sedimentary rocks such as sandstone, siltstone, shale, mudstone and limestone. Sedimentary rocks cover three-quarters of the earth's land area, which means that fossils can be found all over the world, and people can find all kinds of animal and plant fossils in mountains, valleys, deserts and plains. Generally speaking, the lower the horizon, the older the fossil, the higher the horizon, the more evolved the preserved fossil and the more complex its structure.
△ Rock outcrops in the origin of Luoping biota fossils (Source: Chengdu Geological Survey)
In life, many fossils have been found around us. For example, there are many brachiopod fossils on the cylindrical surface of the hall of Nanjing Paleontology Museum, and even the stem fossils of sea lilies were found in the public square of Nanjing Gulou. Some fossils were found in residents' homes. The first discovery of the famous Ediacara biota in China was accidentally discovered by an expert from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, on a slate with a newly changed roof in Yichang, Hubei Province, leaving an anecdote about the discovery of rare fossils. In 1950s, researchers in geological museum, China also found the famous Guizhou dragon fossils on the slate roofs of local houses.
△ The oldest footprint fossil was found in the Ediacaran strata in the Three Gorges area (Source: Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences)
A complete fossil collection process, including preparation before departure, fossil search and excavation, and final fossil treatment and identification. The overall requirements of collection and observation are quantity and quality, and the specific requirements depend on the research task. For example, biostratigraphic research requires selecting a good profile, searching and collecting fossils layer by layer, measuring, observing and recording lithology and fossil output layer by layer, cataloguing and packaging rock and fossil samples. If you are doing paleontological research, in addition to general biostratigraphic work, you should also focus on observing and collecting data such as the distribution, burial and community structure of paleontology, often carry out quantitative collection and observation in the field, and make more sketches and photos.
Before you set out to look for fossils, you should be fully prepared. First of all, we should choose the field work area and understand the basis of the preliminary work. Then prepare a geological map, and have a full understanding of the stratigraphic distribution and geographical topography of the working area. At the same time, collect information about fossils or their origin through the Internet, see where the fossils you are looking for have been exposed, or learn about fossil sites through local people, which can get twice the result with half the effort.
In addition, the equipment for field work should be prepared: geological backpack, geological hammer, magnifying glass, paper strip, brush, adhesive tape, wrapping paper and collection bag. The geological hammer should have a chisel tip, which can be used to dig the fossils on the outcrop of the section or to split the specimens along the natural plane. As for materials, remember to prepare shoes and clothes suitable for field work. Of course, food and water are also essential. If you work in the field for a long time and stay away from the city, you need to prepare sleeping bags and tents.
△ Geological Hammer (Source: Baidu Encyclopedia)
When working in the field, you should be good at finding fossil outcrops. Although fossils are buried underground, crustal movement always exposes some fossils to the surface. Nowadays, mountains and roads are being built everywhere, revealing a large number of geological sections and fresh outcrops. Of course, naturally formed riverbeds, cliffs and gullies are all good places to look for fossils, because these places are exposed to the surface of the earth under the weathering of nature, just like disemboweling. The dinosaur fossils at the keel tip in Shandong Province were found in ravines.
In addition, it is also important to have some field observation experience. For example, field observation should pay special attention to tuberculosis, which is generally composed of iron, calcium and phosphorus. Quaternary mammal fossils are often found in tuberculosis, and the toothfish fossils in Jurong, Jiangsu Province are typical examples preserved in tuberculosis. When looking for vertebrate fossils in the field, it is easier to find fossils in places where the stratigraphic level changes greatly, especially in some mound piles with interbedded sandstone conglomerate, and the colors of the rocks are also different. Caves are usually a treasure house for preserving mammalian fossils, and many mammalian fossils and ancient human fossils have been found. Two ancient human skull fossils, accompanied by a large number of mammalian fossils, were found in Tangshan Ape Cave, Nanjing.
△ Fistula fossils (Source: Baidu Encyclopedia)
However, it is not easy to bring fossils from the wild to the indoor, and some equipment is needed to make these prehistoric life come to light and enter their own collection room intact. After collecting fossil specimens, it is usually necessary to do necessary treatment to remove unnecessary dust and surrounding rocks. For fossils that are not easy to be broken, they can be washed with water or brushed with a soft brush, and then according to the size and fragility of fossil specimens, various suitable excavation tools, such as chisels and fine needles, are selected for preliminary repair. For fragile specimens, be especially careful, wrap them in multi-layer paper and put them in collection bags. When wrapping fossils, remember to write clearly the collector, collection place, latitude and longitude, date, etc. The relationship between fossil specimens and the occurrence of surrounding rocks is described preliminarily.
The indoor stage includes the identification, description and special study of fossils. Identification and description include a series of procedures such as polishing, restoration, identification and photographing, and fossils will be named, classified and described according to regulations. On this basis, carry out special research in a certain subject direction.
With the development of society and the progress of science and technology, people can now easily reach remote areas that were difficult to reach before by means of transportation extending in all directions, accurately locate wild fossil points by mobile phones, and even help to understand the outcrops in wild areas with the help of drones. In indoor research, there are various advanced physical and chemical facilities and means to deal with fossils, and many advanced observation and detection instruments such as electron microscope are used to study fossils.
It must be noted that it is also important to understand the Regulations on the Protection of Paleontological Fossils promulgated by the state, which clearly stipulates that no unit or individual may collect paleontological fossils that have been illegally obtained or whose legal sources cannot be proved.
In short, fossil discovery is always in progress, and understanding the life history of the earth requires the joint efforts of scientists and fossil lovers. The discovery of more fossils in the future will enrich and deepen people's understanding of the earth and life.