Introduction on Fossils

What is a fossil?
Fossils are the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas, lakes and rivers. Fossils also include any preserved trace of life that is typically more than 10 000 years old.

Soft body parts decay soon after death, but the hard parts, such as bones, shells and teeth can be replaced by minerals that harden into rock. In very exceptional cases, soft parts like feathers, plant ferns or other evidence of life, such as footprints or dung, may also be preserved. Remains can include microscopically small fossils, such as single-celled foraminifera or pollen grains, as well as more familiar fossils such as ammonites and trilobites.