In the eyes of paleontologists, the skeleton fossils scattered in the loess are not just a pile of dead objects. They are like scattered puzzles. They are pieced together, maybe a flying dinosaur, or A huge whale may also be just a primitive human skull or a bug at the origin of life. But biologists don't have a glare, how do they know where there are fossils? Is there any instrument that can detect fossils in the ground? How do they know the names of these creatures?
Find
Paleontology is an ancient and traditional basic science that studies fossils of organisms that have appeared on Earth to understand the origin, evolution, extinction, and recovery of organisms in geological history and their relationship to the environment at that time. It generally goes through several stages, such as field trips, fossil excavations, specimen repairs, scientific research, morphological restoration, and museum exhibits.
Before field trips, first select areas and strata. For example, study pterosaurs and dinosaurs, and find fossil clues in the Mesozoic strata. The Mesozoic includes the Triassic, Jurassic, and Cretaceous, while the pterosaurs and dinosaurs crawl. Animals only live in the Mesozoic, so their fossils cannot be found in the deposition of later Cenozoic and earlier Paleozoic.
In the wild, not only to find and verify the location of the fossils recorded in the geological literature, but also to visit the local fellows, to investigate whether the fossils were found in this area and when they were discovered. On this basis, looking for possible fossils, therefore, the search for the fossil clues in the field and the determination of the location of the excavation are not dependent on advanced equipment.
Determine the best excavation site, mainly based on the number of fossils exposed to the surface, and the rock layers buried in the fossil to analyze whether the fossils of this rock layer are intact or relatively intact individuals buried in the original, or are dispersed and dispersed in different places. Bone, is the enrichment burial caused by cluster death, or a small amount of burial formed by normal death. For example, the Rehe Biota in western Liaoning is different from the Laiyang dinosaur fauna in Shandong. The former is distributed in lake sediment shale, which is gray-black shale, which means that they are formed in the deep lake static water reduction environment. The fossils found in the shale are generally intact individuals, and judging from the large number of volcanic ash interbeds on the section, the volcanic activity here is very frequent, and the death of these creatures should be related to the catastrophic events caused by volcanic eruptions. That is to say, they are dead in an abnormal cluster. As long as the layers and locations of fossil outcrops are found, it means that there are a lot of complete fossils buried in them. Therefore, we can not hesitate to find even one outcrop of bones. This location is identified as the best place to discover. The latter is buried in the sand-shale rock formed by the alluvial river. It is a purple-red pebbly sand mudstone piled up in a disorderly manner. It belongs to the sedimentary type formed by the debris flow under the oxidizing environment. Most of the fossils in this type of sediment are scattered and preserved, so the most The location of the fossil stone should choose the point where the fossil outcrop is the most in the same layer. The more outcrops are, the more enriched the fossils are.
Acquisition
It is important to find fossils in the wild, but it is even more important to collect the fossils that are found intact. Depending on the lithology of the fossil-bearing strata, the burial environment, etc., different collection methods can be adopted, such as the box method, the gypsum bag and the “sandwich biscuit method”.
The collection of fossils such as large dinosaur skeletons scattered in the river alluvial burial environment like the Laiyang dinosaur fauna in Shandong, most of them use the gypsum package method. This method is to sag downward around the fossil and surrounding rock. When it exceeds the fossil, it shrinks inward, making it a mushroom shape. Pour the plaster on it, cover it with a sack piece, and then pour it on a thick plaster. , smoothing and compacting, plus wooden boards or wooden sticks, etc., the gypsum heats up and hardens, and the steel brazing is separated from the rock layer and turned over, and the number is registered.
For the complete fossil skeleton buried in the shale of the Liaoxi Lake, it is necessary to adopt the "sandwich biscuit method". Because the shale of the fossils of the Rehe Biota in the western Liaoning has many fissures, it contains volcanic ash components. The rock layers are very soft under long-term immersion in the groundwater. After the collection, the volcanic ash will dehydrate rapidly and the rock formation will be deformed and powdered. Therefore, Collecting such specimens has always been a problem. However, the "Sandwich Biscuits Method" can collect more than ten specimens a day without any damage to the fossils. This method is to determine the scope of the individual fossils found. Cut the gaps around the fossils and surrounding rock with a knife and cut out the small grooves. Place a soft paper around the specimen along the groove, tightly wrap it with a transparent tape, and separate the under the fossil layer. Relatively loose layer, the specimen is translated along the level to the prepared wooden board, then the soft paper is put on the other board, and the other wooden board is pressed and wrapped with tape, leaving only the small gap of evaporation steam, and finally dehydrated and dried.
Fossil repair is one of the most critical aspects of paleontology research. Fossil repair is to expose the fossil skeleton as much as possible without damage to the fossil. For example, when repairing fossils collected by the Sandwich Sandwich Method, open the thoroughly dried specimens from the upper level of the bones found in the field and repair them along the exposed bones. Some of the specimens also contain dinosaurs or birds. Category