What fossils are there?

Fossils in strata can be roughly divided into four categories according to their preservation characteristics: solid fossils, die-casting fossils, trace fossils and chemical fossils.

Solid fossil

Refers to fossils that are almost completely or partially preserved by paleontological remains themselves. Protozoa can avoid air oxidation and bacterial corrosion under particularly suitable conditions, and their hardware and software can be completely preserved without major changes. For example, the mammoth (found in the frozen soil of Siberia during the Quaternary Glaciation 190 1 year ago, not only the bones are intact, but also the skin, hair, flesh and blood and even the food in the stomach are well preserved).

Die-casting fossils

It is the imprint or recasting left by biological remains in strata or surrounding rocks. One kind is imprint, that is, the imprint left by biological remains after they fall to the bottom of the water. The remains are often destroyed, but this imprint reflects the main characteristics of organisms. Creatures without hard shells can also preserve their soft impressions under certain geological conditions, the most common being the impressions of plant leaves. The second category is impression fossils, including external model and internal model. The external model is the trace of the hard part of the relic (such as shell) printed on the surrounding rock, which can reflect the original biological appearance and structure; Internal model refers to the traces of the internal contour structure of shells printed on surrounding rocks, which can reflect the internal morphology and structural characteristics of biological hardware. For example, when a shell is buried in sandstone, its internal cavity is also filled with sediments. When the sediment solidifies into rock and the shell is dissolved by groundwater, the outer mold of the shell remains on the contact surface between the surrounding rock and the shell surface, and the inner mold remains on the contact surface between the surrounding rock and the shell surface. The third type is called core, and the sediment filler in the shell mentioned above is called core. Its surface is an internal model. The shape and size of the core is equal to the size of the internal space of the shell, and it is an entity that reflects the internal structure of the shell. If there is no sediment in the shell, when the shell dissolves, it will leave a space with the same shape and size as the shell. If this space is filled again, it will form an entity with the same shape, equal size and uniform composition as the original shell, which is called the outer core. The shape of the outer core surface is the same as that of the original shell, and it is printed by the outer mold, but its interior is solid, which can not reflect the internal characteristics of the shell. The fourth is casting mold. When the shell is buried in the sediment and the outer mold and the inner core have been formed, the shell is completely dissolved and filled with another mineral, so that the filling keeps the original shape and size of the shell, just like the casting process, thus forming the casting mold. Its surface is the same as the original shell, and there is a core inside them, but the fine structure of the shell itself has not been preserved.

Generally speaking, the concave and convex patterns of the outer mold and the inner mold are just the opposite of the original. The external shapes of the outer core and the mold are completely consistent with the original, but the internal structure of the original is destroyed and disappeared, and its material composition is also different from the original. As for the difference between the outer core and the mold, the former has no inner core, while the latter also contains an inner core.

Trace fossil

Refers to the traces and remains of ancient life activities preserved in rock formations. The most important trace fossils are footprints. In addition, there are traces of crawling, caves, drilling holes of arthropods and hidden caves formed by tongue-shaped shellfish living in coastal areas, which can form trace fossils. In terms of trace fossils, it often refers to animal excrement or eggs (egg fossils); The dung balls and particles of various animals can form dung fossils. Dinosaur eggs in Cretaceous strata in China are world-famous, and nests of dinosaur eggs have been found in Laiyang, Shandong Province and Nanxiong, Guangdong Province.

chemical fossil

Although the remains of some ancient creatures have been destroyed and not preserved, amino acids, fatty acids and other organic substances formed by the decomposition of organic components that make up the creatures can still remain in the rock strata. This kind of fossil is invisible, but it has a certain chemical molecular structure, which is enough to prove the existence of past organisms. This kind of fossil is called chemical fossil. With the progress of modern chemical research and the improvement of science and technology, the organic molecules of ancient organisms (referring to amino acids, etc. ) can be separated from rock strata for identification and research, and a new discipline-paleontology has emerged.

What fossils are there in the world?

Due to different species, different formation conditions and different preservation processes, there are many types of fossils, but in general, they are nothing more than the following four:

1. Solid fossils refer to fossils in which organisms themselves have been partially or completely preserved.

There are several preservation methods: one is resin preservation, mainly amber fossils, and the objects of preservation are mainly ancient arthropods; Second, pit and marsh preservation, such as animals trapped in peat bogs and asphalt pits, is mainly for ancient terrestrial vertebrates; Third, frozen preservation, such fossils are relatively young, such as some large Quaternary vertebrate paleontology in Siberian permafrost; Fourth, petrochemical (see Fossil Formation for details);

According to the texture of fossils, there are some types, one is "unchanged solid fossils", and the soft parts of these fossils are well preserved or intact, such as mammoths, some amber and some mummy fossils. This kind of fossil is of great research value. The second type is "micro-hardened stone", which has lost its soft tissue, but left some slightly degenerated hard tissue parts (teeth, crustaceans, exoskeletons, etc.). In addition, the original mineral components in the organism have been preserved. Although it has been slightly petrified, some biological structures are still well preserved. Most of these fossils are invertebrates, such as trilobites and shellfish. The third is fossil fossils "(see Petrochemical for details).

2. Die-casting fossils This refers to the imprint and recasting left by organisms in the bottom material, surrounding rocks and fillers. It can be subdivided into several types: first, imprint fossils, second, impression fossils, third, mold fossils, and fourth, reproduction fossils. Which one belongs to mainly depends on the relationship between fossils and their surrounding rocks.

3. Trace fossils Trace fossils refer to traces and remains left on the surface or inside of sediments due to paleontological activities, such as animal footprints, scratches, crawling marks and excavated caves, as well as fossils such as eggs, animal feces and stomach stones. From a broader perspective, such fossils should also include labor tools and cultural relics of ancient human activities.

4. Chemical fossils This means that although ancient organisms have not been preserved, the organic components that make up the organisms are decomposed to form various organic substances (amino acids, fatty acids, etc.). ) but is preserved in the rock, so that we can judge the existence of an ancient creature.

What fossils are there in China?

In fact, China used to be the "kingdom" of dinosaurs, and now it is also an important producer of dinosaur fossils in the world.

It is understood that more than 70% provinces in China have dinosaur fossils, ranging from Shandong Peninsula in the east to Tianshan Mountains in the west, Gobi Desert in Inner Mongolia and Baishui in Heilongjiang Province in the north, and subtropical Yunnan and Guangdong in the south. It is recognized as a big producer of dinosaur fossils in the world, with Jurassic and Cretaceous dinosaur fossils as the main ones. Up to now, dinosaur fossils of different periods have been found in Shandong, Xinjiang, Sichuan, Yunnan, Ningxia, Guizhou, Heilongjiang, Henan and other places. Among them, the late Triassic dinosaur fossils were found in a few areas such as Lufeng Basin in Yunnan. Jurassic dinosaur fossils were found in Sichuan, Yunnan and Guizhou. Cretaceous dinosaur fossils are mostly found in Inner Mongolia, Heilongjiang, Shandong and other places in northern China.

What's the use of fossils?

1 Great scientific research value: Fossils are the remains or remains of various organisms in the distant geological history, so fossils can more or less reflect the living conditions of organisms and their living environment at that time, which also provides important clues for human beings to understand the life history and ecological environment change history on the earth. Through the study of fossils, scientists have made us have a deeper understanding of the living environment, lifestyle, evolution law and mechanism of paleontology. The study of biostratigraphy, molecular paleontology, paleontology and paleobionics is also inseparable from paleontological fossils. It can be seen that all aspects of paleontology and scientific research of some related disciplines are inseparable from paleontological fossils!

2. Wonderful aesthetic value: Many beautiful fossils are natural heritage and natural works of art ... Many of these fossils are really great!

Social culture: Collecting fossils means understanding natural history and other scientific knowledge, and also plays a role in cultivating self-cultivation and cultivating sentiment. The activities of fossil lovers and collectors not only played a certain role in popularizing science, but also promoted the development of paleontology to a great extent. For example, in recent years, many major paleontological discoveries that caused a sensation in the world in western Liaoning, China, were initially related to some fossil collectors.

References:

Cazx/lldlm/ China Vision/China Vision /yt

What is a fossil?

In layman's terms, fossils are stones made from the remains or remains of creatures living in the distant past. In the long geological era, countless creatures have lived on the earth. The remains or lives of these creatures after death are all traces left behind, and many of them were buried by the sediment at that time. In the following years, the organic matter in these biological remains was completely decomposed, and the hard parts, such as shells, bones, branches and leaves, were petrified into stones with the surrounding sediments, but their original shapes and structures (even some subtle internal structures) remained; Similarly, the traces left by those creatures when they are alive can be preserved in this way. We call these fossils biological remains and remains fossils. By studying fossils, scientists can gradually understand the form, structure and category of organisms in the distant past, infer the origin, evolution and development process of organisms in the past ten thousand years, and restore the earth's ecological environment in various stages of the long geological history.

References:

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What are the five fossils of dinosaurs?

Footprints, dinosaur eggs, bones, feces, teeth

What kinds of fossils are there?

Fossil has always been called a strange stone to record time. All along, various fossils have emerged in the fossil market. Common fossils are wood fossils, paleontological fossils and marine fossils. Three common paleontological fossils in western Liaoning are fish fossils, coral fossils and jadeite snails.

What's the difference between fossils and ordinary stones?

Today, we can't artificially create fossils in a strict sense through experiments, but we can reveal the process of fossil formation through simulation or study of strata. The discipline that focuses on the burial and fossilization of biological remains, relics and remains is called burial science in the branch of geological history.

Burial science tells us that in the process of life evolution on the earth for various reasons, only a few have been preserved to form fossils because of adapting to the geological environment, and most of them have been unable to know their existence. Fossil formation generally meets the following necessary conditions:

1. Organisms must have certain hardware, including bones, teeth, shells, stems, veins, spores and pollen. Of course, there are also very exceptional cases, such as jellyfish marks.

Rapid burial

Creatures are quickly buried for special reasons even when they are alive after death. In this way, they are well preserved because they can avoid the action or destruction of decomposers, machinery and chemicals.

3. Long years

Petrochemical itself is a very long process. In this process, there may be some situations: buried in situ, the crustal activity is relatively stable. In this case, fossils are generally rich and complete, such as the famous asphalt pit fossils in North America; Buried in different places, after the death of organisms, they have been transported from A to B for various reasons, and most of these fossils have been damaged to varying degrees.

Detailed explanation of petrochemical process ......

Due to different species, different formation conditions and different preservation processes, there are many types of fossils, but in general, they are nothing more than the following four:

1. Solid fossils refer to fossils in which organisms themselves have been partially or completely preserved.

There are several preservation methods: one is resin preservation, mainly amber fossils, and the objects of preservation are mainly ancient arthropods; Second, pit and marsh preservation, such as animals trapped in peat bogs and asphalt pits, is mainly for ancient terrestrial vertebrates; Third, frozen preservation, such fossils are relatively young, such as some large Quaternary vertebrate paleontology in Siberian permafrost; Fourth, petrochemical (see Fossil Formation for details);

According to the texture of fossils, there are some types, one is "unchanged solid fossils", and the soft parts of these fossils are well preserved or intact, such as mammoths, some amber and some mummy fossils. This kind of fossil is of great research value. The second type is "micro-hardened stone", which has lost its soft tissue, but left some slightly degenerated hard tissue parts (teeth, crustaceans, exoskeletons, etc.). In addition, the original mineral components in the organism have been preserved. Although it has been slightly petrified, some biological structures are still well preserved. Most of these fossils are invertebrates, such as trilobites and shellfish. The third type is "chemical petrochemical" (see chemical petrochemical).

2. Molded fossils

This refers to the imprint and recasting left by organisms in sediments, surrounding rocks and fillers. It can be subdivided into several types: first, imprint fossils, second, impression fossils, third, mold fossils, and fourth, reproduction fossils. Which one belongs to mainly depends on the relationship between fossils and their surrounding rocks.

3. Trace fossils

Trace fossils refer to traces and remains left on the surface or inside of sediments due to paleontological activities, such as animal footprints, scratches, crawling marks and excavated caves, as well as fossils such as eggs, animal feces and stomach stones. From a broader perspective, such fossils should also include labor tools and cultural relics of ancient human activities.

4. Chemical fossils

This means that although ancient organisms have not been preserved, the organic components that make up organisms are decomposed to form various organic substances (amino acids, fatty acids, etc.). ) but is preserved in the rock, so that we can judge the existence of an ancient creature.

Secondly, according to the size of fossils, fossils can be divided into macroscopic fossils, microscopic fossils and ultramicroscopic fossils. Generally speaking, those fossils that can be studied without a microscope are called giant fossils, and they are also the ones that people know the most. Microfossils refer to those fossils that need to be observed and studied with a microscope. People generally don't know much about these fossils, such as foraminifera, radiolarians, ostracods and diatoms. Of course, they also include some tiny parts of prehistoric creatures' body structures, such as conodonts and tiny fish scales, as well as spores and pollen of plants. It should be noted that some scholars may ... what stones are there in the world?