Fossils are the conserved remains or traces of the ancient animals, plants or other organisms. The sedimentary rock is a type of rock that is found commonly. The sedimentary rocks have several layers. Within these layers, one can find different fossils.
Fossils take several thousands years to make. Over the years, the bones of the dead animals undergo mineralization; this mineral replacing procedure fossilizes the remains of the organism or leaves a print of the dead organism in the sedimentary rocks. Entire bodies of plants, animals and birds have been fossilized in this manner over a period of thousands of years. Sometimes the footprints, tracks, trails and burrows have also can be found as fossils.
Soft and stable sand can turn into very rigid fossil. But this procedure is bit different. In this case, the pressurization of the sediments played the key role. The temperature is also a very important part of this procedure. The temperature of the earth increases by about 1° C per 100 feet or 31 meters.
The average pressure increases about 1 pound per square inch for each foot or 31 centimeters. This increase in pressure and temperature is known as the compaction. By this procedure, the fragile particle of the sediment becomes rock. Sometimes some unusual things such as the wings of the butterflies or the compound eyes of insects can be found in the layer of the sediments as fossils. The process by which coal is formed inside the earth is dependent on the various layers of the earth’s crust. Even in the layers of coal sometimes fossils may found.
Some more data on fossils
The totality of fossils and their placement in the fossiliferous rock is named as “Fossil record”. Most of the fossils have a minimum age. The fossilization process started several billion years ago. Most of the fossils are at least 10,000 years old. The geologists have different methods to detect the actual age of a particular fossil. The development of the radiometric dating is one of the procedures. By this procedure, a geologist can determine the numerical age of the strata/ sedimentary layer and the fossils.
The early naturalists have good understanding about the similarities and differences of the living species to develop a classification system which is still in operation. Darwin was the first scientist who linked the structure of the great tree of life in “living organism” with then very unused fossil records. He also described a process of descent with modification or evolution by which the organism has the ability to adapt to the various natural and environmental changes and can undergo change or mutate.
The latest analysis
The earth’s climate, atmosphere, oceans and intervallic disasters invoked the selective pressure on all organisms. While many organisms were able to adapt, others died out without mutation or underwent mutation. The study of the fossils can help to understand how organisms have evolved and how they are linked to the present-day organisms. The phylogenetics and paleontology scientists are working together for understanding the appearance of early life and evolution.