Description:
Fossils in ancient times can restore the real situation at that time through archaeological excavation, which is the first-hand information for studying the production and life of ancient humans.
Introduction to fossils:
Fossil is the main research object of paleontology, which provides evidence for studying the life history of animals and plants in geological period. Records of fossils in ancient books in China, such as Ji Ran in the Spring and Autumn Period and Wu Jin in the Three Kingdoms Period, all refer to the "keel" produced in Shaanxi, that is, the bones and teeth of ancient vertebrates.
Formation conditions:
Organic matter must have hard parts, such as shells, bones, teeth or woody tissues. However, even very fragile organisms, such as insects or jellyfish, can become fossils under very favorable conditions.
Living things must avoid being destroyed immediately after death. If the body parts of an organism are crushed, rotted or severely weathered, it may change or cancel the possibility of this organism becoming a fossil.
Living things must be quickly buried by things that can hinder decomposition. The type of this buried material usually depends on the living environment of organisms. The remains of marine animals can usually become fossils, because marine animals sink to the bottom of the sea after death and are covered with mud.
Fossil classification:
1, 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.
2. Molded 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.
3. Trace fossils
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).