Definition of Fossils | Conditions for preservation | Forms and uses of fossils

Fossils:

The dead remains of preserved plants and animals are known as fossils.

Or

Fossils are the dead remains of the ancient organisms preserved in rocks.

Condition for preservation:

Two conditions should exist for preservation of fossils.

1. Hard parts should be retained.
2. They should be quickly buried.

Forms of fossils:

1. Organism fully preserved.
2. Bony skeletons preserved.
3. Replacement of hard parts.
4. Molds.
5. Casts.
6. Carbonization.
7. Imprints.

Explanation:

If the body is fully buried it lies in class of fully buried organism.

If skeletal bones are buried it lies in class of bony skeletal preserved organisms.

If certain minerals have replaced dead remains then these lie in replacement mode.

Dead remains of plants and animals dissolved in solution and then hollow structure is remained this is called mold.

Molds consisting of minerals produce casts.

Decomposition of minerals is known as carbonization.

Imprints are those fossils in which hard parts are missing.

Uses of fossils:

1. To determine ages of rocks.
2. To differentiate about deposits.
3. Gives information about climate.