Detailed data of paleontology

Paleontology is a branch of geology and an interdisciplinary subject between life science and earth science. It is not only a unique branch of life science with the nature of historical science, but also an important foundation and component of historical biology, such as the origin, development history, macroevolution mode, rhythm and mechanism of biology. It is also a branch of earth science, which studies the biological remains, remains and fossils preserved in the stratum to determine the sequence and age of the stratum, understand the history of crustal development, and infer the land and water distribution, climate change and the formation and distribution law of sedimentary minerals in geological history.

Chinese name: Paleontology mbth: Paleontology /PAL (a) Paleontology discipline: geological types: branch, brief history of development, research methods, observation objects, identification and description, biological evolution, progressive evolution, stage evolution, classification system, theory, functional morphology, architectural morphology, paleopathology, paleogeography, mathematics, chemistry, paleontology, molecules, biology. With the development of modern production and the deepening of scientific research, paleobotany has been divided into paleopalynology and paleophycology; Paleozoology is divided into paleoinvertebrate zoology and paleovertebrate zoology; Paleoanthropology is not only a branch of anthropology, but also a branch of vertebrate paleontology. According to the study of individual micro-animal and plant fossils or micro-parts of large organisms, a branch of micro-paleontology has been formed, which shows great significance in theory and practice. A Brief History of Development Both China and the West have a history of 1000 years. However, paleontology began to become a science in the late18th century, with a history of about 200 years. The founders of this science include: J.-B. De Lamarck (invertebrate zoology), W. Smith (biostratigraphy), G. Ju Ye Wei (who put forward the laws and concepts related to extinction and catastrophe) and C. R. Darwin (whose theory of evolution provided a scientific theoretical basis for paleontology and pointed out the defect of "incomplete fossil record"). From then on to the middle of the 20th century, the mainstream of paleontology was to describe paleontology and biostratigraphy. The achievements in this respect are enormous. First, Western Europe and North America, then the Soviet Union, Eastern Europe, China, India and even other parts of the world published a large number of monographs on paleontology and biostratigraphy, which provided factual basis for the comprehensive study of paleontology. The development of other aspects of paleontology in this period is not remarkable, one of the reasons is that the development of modern biology (genetics and molecular biology) has not penetrated into it, and there is also a lack of a unified theoretical framework, which can point out the direction for paleontology in geology. Paleontology Since the middle of the 20th century, paleontology has made some major breakthroughs: ① The application of electron microscope and special photography technology and the need of petroleum exploration have made some new branches of disciplines develop by leaps and bounds, including micro-and ultramicro-paleontology, paleontology, fossil petrology and so on; (2) Based on the accumulation of a large number of data, the work of paleontology theory has made a leap, which was first synthesized by Simpson and Meyer based on genetics and evolution. After 1960s, plate theory provided a unified global geological background for paleontology, and put forward requirements for paleontology. Due to some new developments in biology (neutral theory, cladistic taxonomy, etc. ), paleontology has seen many new trends of thought in evolution, systematics and paleogeography. The impact on traditional ideas has produced some new achievements, for example, the total fin fish may not be the ancestor of quadrupeds without internal nostrils. Research methods: The research object of paleontology is fossils. Fossil research includes two stages: field and indoor. The field stage is mainly to collect specimens and observation data. 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, looking for and collecting fossils layer by layer, measuring, observing and recording lithology and fossil output layer by layer, cataloguing and packaging rocks 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. The indoor stage of identification and description of paleontological specimens includes fossil identification and description and special research. Appraisal description includes a series of procedures such as polishing, repairing, appraisal, photographing and description. The classification and description procedures used are the same as those used in biology, and the naming methods (binomial method, priority rule, etc. ) also followed the provisions of the International Regulations on the Naming of Animals (Plants). On this basis, carry out special research in a certain subject direction. The evolution of biological paleontology is a creature in geological history and follows the principle of Darwin's evolution theory. The evolution modes pointed out by the theory of evolution-branch evolution, stage evolution, radiation adaptation, divergent evolution, convergent evolution, parallel evolution and dynamic evolution are also applicable to paleontology. In addition, the evolution of paleontology has its own laws and characteristics. The more important laws are: ① the law of irreversibility, which was put forward by Belgian paleontologist L. Dolo. It points out that once an organism or its organs have evolved, they will never recover in the later biological world, and once they disappear, they will never reappear in future generations or other places. For example, after fish evolved into terrestrial mammals, some mammals returned to the ocean and became whales, but the fins and gills of fish could not be recovered in whales. Whales could only breathe by lungs and use their evolved limbs and tails to play the role of fins. According to the law of irreversibility, the extinct fossil species in the older strata will not reappear in the newer strata, and there must be different fossil biota in the strata of different times. The combination of sequence law and irreversible law constitutes the basic principle of paleontological method to determine stratigraphic age and divide strata. (2) related laws, put forward by the French paleontologist G. R. Ye Wei. It points out that the development of various parts of an organism is closely related to each other, and the change of one part will also cause corresponding changes in other parts. This is because the adaptation to the environment will inevitably affect many aspects. For example, the adaptation of mammals to meat will cause a series of related changes, such as tooth differentiation (adaptation to biting), strengthening of upper and lower jaws, keen sense, strong limbs and claws on toes. According to the relevant laws and the knowledge of comparative anatomy, we can recover the complete fossil data from the usually incomplete preservation, and infer its ecological habits accordingly, so as to restore the ancient environment. (3) the law of repetition, put forward by German biologist Heckel. It points out that individual development is a simple repetition of systematic development. According to the recursive law, we can trace the phylogeny of the group to which the organism belongs from the individual development, thus establishing the pedigree, which is helpful to correct classification. For example, if we slice some single corals from infancy to adulthood, we can see that the internal structure is single band at first, then double band, and finally becomes three bands. This shows that the phylogeny of three-zone four corals has gone through the process from single-zone type to double-zone type and then to three-zone type. Gradual evolution of paleontology The evolution of paleontology is characterized by continuous progress and staged evolution. Progressive evolution refers to the general trend of biological history from less to more, from low to high, from simple to complex. Harlan et al. (1967) increased from dozens of Cambrian to more than 1000 according to the time distribution statistics of 2526 genera and above. Plants, invertebrates and vertebrates show the same trend respectively. In the main taxa of 65,438+06, except gymnosperms, mollusks, brachiopods and reptiles, the degree of differentiation is from low to high, from simple to complex (Chen, 65,438+0978). The evolution of geological stages is a series of alternating processes of short-term abrupt change (discontinuity) and long-term gradual change (balance). The mutation is due to the mass extinction of the old species and the explosive rebirth and radiation adaptation of the new species. After the emergence of new categories, there can be a gradual period of long-term stable development until the next interruption. Mass extinction refers to the extinction of many species in most parts of the earth in the same geological period. At the end of Phanerozoic, the disappearance of Ediacara fauna represented a mass extinction. In Phanerozoic, there were 6 mass extinctions (end of Cambrian, end of Ordovician, end of Devonian, end of Permian, end of Triassic and end of Cretaceous). The one at the end of Permian was the most violent. Every large-scale extinction, the alternation of genera reaches several tens of percent, and the alternation of species is even greater, reaching more than 90 percent. Combined with the radiation adaptation of the next new category, they form the basis for the division of relative geological ages in geological history. The causes of mass extinction can be roughly divided into biological reasons (competition, predation, nutrient sources, nutrient areas, changes in nutrient levels, etc. ), internal reasons (changes in temperature, salinity, climate, oxygen, shallow sea, continental shelf area, etc. ) and external reasons (radiation, impact, magnetic field changes, etc. ). It is believed that the collision of extraterrestrial stars stirred up dust and fog, resulting in comprehensive effects such as shading, cold storage and poisoning, leading to mass extinction at the end of Cretaceous. It is quite popular to say that the mass extinction at the end of Permian was due to the great retrogression of continental shelf area caused by plate splicing. Archaeopteryx is classified in the same order as biology, that is, kingdom, phyla, class, order, family, genus and species, and there are some auxiliary units such as superfamily, superfamily, superfamily, subfamily, suborder and subphylum. The concept of paleontological species is the same as that of biological species, but because fossils can't judge whether there is reproductive isolation, they pay more attention to the following characteristics: ① morphological characteristics of * * * *; ② Form a certain crowd; ③ The population is distributed in a certain geographical range. The fossil species determined according to the above characteristics are considered as the taxonomic units of natural organisms and have objectivity. However, some fossil species are often determined only by the morphology of certain parts of the organism (such as plant leaves); Or after detailed study, it is found that some organisms belonging to different taxonomic units are described under the same name; Or the same taxon has several forms (such as hermaphroditism), but it is given an independent name. These species are called morphological species to distinguish them from natural unit species. The genus also has the same situation. Another difference is that the lowest unit in modern biological classification is geographical subspecies, while there are chronological subspecies in paleontological classification, which refers to populations of the same species with different morphological characteristics at different times. The further development of chronological subspecies became chronological species. Theoretical functional morphology judges function according to bone morphology. Its basic principle is that most forms are the result of adaptation and have functions, and these functions can be inferred through scientific argumentation according to forms. For example, the dividing line between the partition wall and the shell of cephalopods-suture line-has become more and more complicated in the process of evolution. Three hypotheses are put forward: ① Folding increases the strength of the shell to resist the pressure difference caused by rapid fluctuation; (2) The folded part is the muscle attachment, and the muscle expansion makes the animal body advance and retreat to change the specific gravity of the whole shell and adjust the lift; (3) Mantle fold increases the area of gas-liquid secretion and adjusts the elevation. The diaphragm fold is the result of mantle fold. According to three hypotheses, the reasonable performance is inferred and verified by the geological historical evolution and individual development of suture. It is proved that the latter two hypotheses cannot be established, and the first hypothesis is more reasonable, which makes clear the function of suture fold. The study of functional morphology can be extended to the inference of paleoecology and paleoenvironment. For example, some people think that dinosaurs are not warm-blooded animals, or make judgments based on functional morphology. The image construction morphology of paleontology was put forward by German paleontologist S. Seilacher and others from the further development of functional morphology. It is believed that the formation of biological skeleton is based on three factors: ① historical factors, that is, systematic development, determine the genotype of organisms through reproduction, that is, determine the materials of organisms and bones; ② Functional factors, namely adaptation, determine the direction of organism and skeleton construction through natural selection of population and species; ③ The morphogenetic factor, namely growth, determines the growth mode of organisms and bones through biochemical processes. For example, the construction process of modern horseshoes depends on: ① adapting to the needs of running on the grassland; ② Its ancestors were three-toed; ③ During the morphogenesis of an individual, other toes degenerate and the middle toe develops into a hoof. Based on this, the phylogeny, environment and morphogenesis can be inferred from the architectural morphology of bones in turn. Paleopathology is a science about pathological phenomena in fossil remains. Most of them are confined to vertebrates, and the known pathological phenomena include overgrowth, tooth deformity and dental caries, fracture and callus, osteonecrosis, new joint hyperplasia, odontoma, hunchback, osteomalacia, osteomyelitis, periostitis, osteoarthritis, bone and jaw hypertrophy, spinal deformity, bone tuberculosis and so on. , mainly in dinosaurs and mammals. Pathological phenomena of plants and invertebrates have also been reported, such as parasitic diseases of mollusks. Palaeogeography studies the geographical distribution of paleontology. It develops rapidly and is widely used in the reconstruction of paleogeography and paleoenvironment, the history of plate movement and even the discussion of mineral formation and distribution. The main research content is the palaeogeographic flora of each era, and the Phanerozoic flora of the world has begun to take shape. Flora is generally divided into regions or boundaries, regions, sub-regions or provinces, and some are further divided into sub-provinces and local centers. The division of flora varies from family to family. Generally, the division of large areas and regions pays more attention to latitude, temperature control and geographical barrier control. In the lower flora unit, the difference of biological community often plays an important role, so it overlaps with paleoecology. Valentin (1973) regarded paleogeography as an intercontinental and global paleoecology. Palaeogeography not only studies flora, but also studies the diffusion, distribution, migration, isolation and mixing of paleontology. This work is deepening. Combining the theory of discontinuous equilibrium and cladistic systematics, alternative differentiation biogeography emerged, which holds that the distribution of organisms is not a process of spreading outward from the origin center, but a process in which an ancestor group branches into two sister groups due to geographical isolation, and the branch point represents the ancestor group in genealogy and the barrier in geography. Its analysis method is the same as that of cladistics, that is, to find the relationship between two regions is closer to that with any third region, so as to establish the closeness (historical order) of the interconnection between the distribution areas of biological groups. Mathematical methods have been used in various fields of paleontology. There are many applications: using mathematical methods and computers to identify, describe and count fossils; Using mathematical methods such as univariate and bivariate analysis and corresponding coordinate diagrams to study population variation and population dynamics; Digital classification; Quantitative paleoecology, etc. The study of chemical processes and their products related to paleontological activities. There are roughly two directions: one direction focuses on the study of organic matter in fossils and sedimentary rocks, and uses them as chemical fossils to explore the evolution law of chemical organic matter in geological history. Finding and studying this chemical fossil in the oldest rocks is of great significance to exploring the origin of life on earth. The other direction is to study the chemical composition of paleontological bones, especially its mineral composition, trace chemical composition and isotopic composition. These results can be used to study: ① the evolution history of seawater hydrochemistry; ② Determination of paleoenvironmental parameters (salinity, temperature) of seawater; (3) Petrochemistry and diagenesis with fossils as the main components, such as carbonate rocks; ④ History of chemical cycle; ⑤ Biological classification based on bone chemistry; ⑥ Bone formation process; ⑦ apply chemical evolution to study chronostratigraphy; (8) The formation and distribution of rare elements (uranium, nickel, vanadium and cobalt) rich in organic matter. Molecular molecular paleontology is a multidisciplinary interdisciplinary field that emerged in the 1990s, involving theories and methods of paleontology, molecular evolution and molecular systematics, geology, geochemistry and other scientific branches. The contents of molecular paleontology research include the basic concepts, techniques, methods, theories and principles of molecular paleontology research, as well as the main research directions and progress abroad, including molecular evolution theory, molecular data processing and analysis methods, ancient DNA, ancient amino acids, molecular markers, molecular systematics, comprehensive research on molecular data of paleontology and modern biology, etc. The development of modern biological research and the improvement of modern technical means have promoted the expansion of traditional paleontology research fields and brought new development opportunities. The research direction of molecular paleontology is to apply the new theories and technical methods of modern biology to the process of paleontology research, such as studying ancient protein molecules and their decomposition products, and determining the arrangement order of ancient amino acids. At the same time, it fully embodies the characteristics and objectives of contemporary paleontology research, and explores the evolution, heredity and chemical composition of paleontology at the molecular level. The determination of amino acid racemization has been applied to the determination of absolute age. Biomineralogy studies the process and result that organisms produce inorganic crystals and amorphous organic and inorganic substances to form bones. On the one hand, the mineral composition and formation mechanism of bones are studied, on the other hand, the microstructure of bones (polygonal columns, staggered slices, nacre, homogeneous layers, etc.) is studied. ). The research results are used for: (1) classification and evolution of paleontological microstructure; (2) Inferring the paleo-marine environmental factors and their changing history. The research fields of paleontology, molecular paleontology and biomineralization partially overlap. Fossil petrology is mainly fossil carbonate petrology. Modern research shows that the formation of carbonate rocks is often related to biological effects, including granulation (bone particles, oolitic particles, fecal particles, nucleated stones, clotted stones, etc. ), mud making (decomposition products of algae or invertebrate bones are the main source of modern gypsum), scaffolding (corals, stromatolites, sponges, etc. Forming a rock frame) and so on. The transformation of carbonate rocks is often related to biochemical process, composition (such as magnesium) and structure (calcite, aragonite, etc.). The biological calcium carbonate skeleton has evolved in geological history. They affect diagenesis through dissolution, metasomatism and recrystallization. This is an important reason why the diagenesis of ancient carbonate rocks is different from that of modern times. Calcareous fossils have been regarded as an important genetic sign of rocks, and thin section study of fossils has become one of the best methods to determine the sedimentary environment of ancient carbonate. Paleobionics explores the advantages of simulating ancient biological physiological structure, which provides a useful reference for modern process design. For example, two positions are designed according to the overlapping tooth sequence of comb-river rafters; The teeth (up to 400 ~ 500) of Duckbilled Dragon are constantly changing, which can be used for the design of grinding and crushing equipment. Traditional paleontology is a branch discipline, which mainly studies the classification and description of paleontological fossils. Usually divided into paleobotany, paleozoology (including invertebrate paleontology and vertebrate paleontology) and microfossils. Among them, microfossils are divided into an independent branch of palynology and a new branch of ultrapaleontology, with ultrafossils as the research object. Ultrafossils refer to microfossils that cannot be distinguished by optical microscope and need to be studied by electron microscope. Generally speaking, their length and diameter are below 10 micron. On the basis of describing the accumulation of paleontological data, modern research gradually turns to biology, which is called modern paleontology or theoretical paleontology. As far as the level of development is concerned, the branches that have been formed are roughly as follows: ① Evolution theory: such as comprehensive theory, that is, modern Darwinism; Discontinuous equilibrium theory. (2) Systematics and taxonomy: including comprehensive taxonomy, cladistic taxonomy and quantitative taxonomy. ③ Morphology: especially functional morphology and architectural morphology. (4) Paleoecology and paleontology. ⑤ Paleopathology. Paleontology is combined with geology, chemistry, physics, mathematics and genetics to form the following disciplines: biostratigraphy and ecological stratigraphy; ② Palaeobiogeography; ③ Mathematical paleontology; (4) Paleontology; ⑤ Molecular paleontology; ⑥ Biomineralogy; ⑦ Fossil Petrology; 8 ancient bionics. Among them, paleontology, molecular paleontology and biomineralization are also regarded as a part of modern paleontology. Paleontology bears the dual task of serving geology and biology. Establishing stratigraphic system and geological year to serve geology: this is the most widely and effectively used aspect of paleontology in geology. According to the sequence law of strata, the process, stages and irreversibility of biological evolution, after decades of efforts, the stratigraphic system from Precambrian to Quaternary and the corresponding geological age system, namely19th century, have been established. Although radioactive dating and other means have been developed since the 20th century, biostratigraphy is still the main means to establish stratigraphic units at all levels. The stratigraphic units corresponding to Mesozoic, Cenozoic, world and geological times are boundary systems, series and stages. For example, the flourishing age of reptiles, gymnosperms and ammonites is divided into Mesozoic, in which the period of dinosaurs and ammonites is Jurassic; In the early Jurassic, there were two super families of ammonites, namely, protoammoniaceae and gymnasiums. Among them, the Serenoman period was characterized by the ammoniacal family of sheep. Several ammonite zones can also be divided under the step. The study of dividing and contrasting strata is called biostratigraphy. Among biostratigraphic methods, the oldest is the standard fossil method. Standard fossils must meet the following conditions: (1) has a short geological age, so as to accurately determine the stratigraphic age; Geographical distribution is extensive, so it is easy to find and compare on a large scale. For example, the goat stone mentioned above can be found in the ancient Mediterranean region all over Europe and Asia, and it is the standard fossil of the Cernorman stage. When using the standard fossil method, it should be noted that any fossil has a process of occurrence, prosperity, scarcity and extinction in time and a process of origin, migration and dispersion in space. The age and geographical distribution stipulated by predecessors and documents need to be revised according to specific conditions, and cannot be mechanically copied. It should also be noted that all kinds of fossils in a biota have different levels of stratigraphic significance, so we can't ignore the face of the whole biota, but only judge the stratigraphic age according to a few standard fossils. In addition to the standard fossil method, there are percentage statistics method, comparison method, quantitative (or graphic) comparison method, etc. As a result of adapting to the environment, restoring paleogeography and paleoclimate, all kinds of creatures have the characteristics of reflecting environmental conditions in their habits, behaviors and body shapes. Therefore, after understanding the morphology, classification and ecology of fossils, we can infer the living environment of their survival period by using the method of "discussing the ancient from the present". Particularly useful in this respect are facies fossils, that is, fossils that can clearly indicate a certain sedimentary environment. For example, reef-building corals live in the ocean, with the water depth not exceeding 100 meters, the water temperature above 18℃, the sea water is clear and the water flow is calm. Therefore, if coral reefs are found in the strata, it can be judged that their sedimentary environment is warm and clear shallow sea. Another example is that pteridophytes live in a warm and humid climate, so the discovery of a large number of pteridophyte fossils in the stratum shows that the ancient climate at that time was warm and humid. When using fossils to restore the ancient environment, we should pay attention to the evolution of the living environment of many organisms in geological period. For example, sea lilies were typical shallow-sea animals in Paleozoic, but now most of them live in the deep sea. In addition, not only facies fossils, but also various biota and sediments themselves have the significance of reflecting the environment, so we should pay attention to comprehensive analysis. Study the origin and distribution of sedimentary rocks and minerals: many sedimentary rocks, such as limestone and diatomite, are mainly composed of fossils, especially energy minerals (oil, oil shale and coal) which are mainly formed by the transformation of animal and plant remains. The application of paleontology in ore prospecting mainly includes the following aspects: ① according to the age distribution and ecological characteristics of ore-forming fossils, the distribution law of minerals is studied; ② Microfossils and nannofossils are widely used to accurately divide and compare ore-bearing strata and guide drilling. ③ From the perspective of paleontology, the law of adsorption, complexation and combination enrichment of rare metal elements by paleontology was studied; To study the role of archaea in mineral formation. Application in geophysics, geochemistry and tectonic geology: the change of the earth's rotation speed causes the change of living conditions of organisms, which is reflected in the change of biological morphology and structure. The ancient biological clock uses the characteristics of biological growth cycle to calculate the change of the earth's rotation speed during geological period. For example, the annual growth period of modern corals has about 360 circles of thin lines, and each circle represents one day. On Devonian coral fossils, the growth of fine lines is about 400 circles, while in Carboniferous it is 385 ~ 390 circles, indicating that the number of days per year is about 400 and 385 ~ 390 days respectively. These data are roughly the same as those obtained by astronomical methods in various geological years. A similar conclusion can be drawn by studying the growth lines of bivalves, cephalopods, gastropods and stromatolites. The calculation shows that the number of days in each year and month has been gradually decreasing since Cambrian, indicating that the rotation speed of the earth is slowing down. In structural geology, the shape and direction of strain ellipsoid are obtained by comparing deformed fossils (brachiopods, graptolites and trilobites) with similar undeformed fossils. In the theory of plate tectonics, there are also many examples of paleontology, such as the division of the southern continent, which can be used to find mesosaurus fossils of freshwater reptiles on both sides. In the study of a series of microplates or terranes, it is more necessary to use related paleontological fossils as the basis for comparison. Paleontology is of great significance for studying the strata formed by deep-sea sediments.