Men have been attracted to fossils since the earliest times. Even today we read with great interest any report about the discovery of the skeleton of some prehistoric animal. The question arises: how can the fragile bones of any animal have stayed preserved for such a long time?
Much depends on the types of soil in which the bones came to rest. If the soil was damp and with a strong acid content, then the bones would not have lasted for very long: the chemicals in the soil would soon have broken them up into a powder.
But a damp soil with no harsh chemicals in it, often acts as a preservative. In this kind of soil the bones are gradually petrified, which means they are turned into stone.
When soil is moist and acid and completely without air, then even the soft tissues of an animal can be preserved through a process similar to mummification.
Picture Credit : Google
