Only a small portion of the organisms that lived in the geologic past have been preserved as fossils. which condition best increases the chance that an organisms will become fossilized?

Fossilization is an extremely slow and complex process, lasting thousands of years. It is also a rare mechanism, since, in order to occur, extremely favorable conditions are necessary for the conservation of the trace left by the organism, such as the following:

Only organisms that have rigid parts, such as bones, teeth, trunks, carapaces and shells, which are the least decomposed, can be fossilized;

There must be a rapid burial of the living being's body, otherwise it will be rapidly degraded by decomposing microorganisms (bacteria and fungi). These remains are usually covered with sand, clay, and other types of sediment, as long as they are not very thick sediments (as these are more susceptible to erosion);

The environment where a fossil forms, for better conservation, must be anaerobic (lack of oxygen), as oxidation contributes a great deal to organic degradation. In addition, the climate must be cold, as the action of decomposing microorganisms decreases greatly at low temperatures.