what is fossil:
Fossils are the petrified remains of organisms that lived in ancient times. The word, as such, comes from the latin fossĭlis, which in turn derives from the verb foderé, which means ‘dig’.
Fossils, are usually preserved in sedimentary rocks. To make an organism in fossil, however, it is necessary that pass by a chemical process called fossilization, which requires a set of conditions and circumstances that rarely occur, and during which the organism could suffer deformations or transformations in its composition.
The importance of the findings of fossils and their study is that they allow us to reconstruct the natural history of the world, collecting data and tracks of the organisms that existed in ancient times.
Science dedicated to the study of fossils is paleontology, from which emerge sub-disciplines as:
Paleobiology: who is in charge of the study of organisms of the past; the biochronology: which analyzes and determines the period in which these organisms lived andthe Taphonomy: dealing with the processes of fossilization.
Fossils, in addition, help in the study of the geology and the evolutionary biology.
Fossil can also be used in a colloquial sense to refer to something that is considered old, outdated or obsolete.
In Mexico, it is called colloquially fossil students going behind with respect to their companions of the initial courses, or who have many years studying without really advancing.
In the past, fossil could also refer to the minerals or rocks of any kind.
As living fossil is known all that currently living organism which keeps great similarity with species in remote times, which only has knowledge through fossil records.
An example of this are it the Brachiopods, that is news from the lower Calambrico, i.e., approximately 540 million years ago. Also is the Coelacanth, a fish that lives off the coast of Africa and that it was thought extinct millions of years did.
As fossil Guide (also called director, index or characteristic) is called the fossil whose presence in an excavation allows to determine with some degree of accuracy the period which from the stratigraphic unit where, well because it is particular of certain period of geological history, because it is its own particular Palaeoenvironment.
As fossil energy or fossil fuel referred to as that which comes from the formed biomass makes million years, through various processes of transformation in the interior of the Earth, until the formation of substances of high energy content.
Some examples of fossil energy coal, oil or natural gas are it. As such, it is an energy extracted from a non-renewable resource. Most of the energy produced in the world comes from these fuels.
Be interested to read about the meaning of renewable resources.