The Remnants of the Past

Fossils are amongst the most fascinating and mysterious phenomena on earth. Explanations about the origins of fossils have been offered since the early 11th century and many theories about fossils exist today. Here¿s a snapshot of the basics of fossils.

What Are Fossils?

Fossils are impressions or remnants of animals and plants that lived on Earth thousands of years ago. These remains can be parts of animals such as bones, teeth, hair, skin, shells and feather, parts of plants such as leaves and roots, and things made by animals such as footprints and even excreta! In order to be considered a ¿fossil¿ a plant or animal remain needs to be at least 10,000 years old!

How Are Fossils Formed?

Fossil formation is somewhat of a miracle. When animals and plants die, their bodies are decomposed rather quickly back into the earth by bacteria or are consumed by scavengers. So, it takes an incredible amount of luck for the remains of a plant or animal to be preserved by nature into a fossil. Fossils can be formed in many ways.

Internment: Remains of animals and plants need to be quickly buried in the soil. More and more soil deposits compress the remains to a point that hard body parts (bones, teeth) become encased by soil. Bones and teeth start decaying and mineralised water creeps into them, replacing the chemicals with soil minerals. After thousands of years, this process results in a rock-like copy of the animal or plant, called a fossil!
Refrigeration: Plants and animals can be frozen in permafrost and become fossilized over millions of years.
Replacement: Cell walls of dead animals and plants can be dissolved over time and then replaced by minerals.