How Do Fossils Form?

What Are Fossils?

Fossils are the remains or imprints left behind from plants and animals. They can be whole parts of an animal, or just pieces of their remains. They can also include movement remnants of animals, such as footprints or imprints.

How Do They Form

In order for a fossil to form, an animal or plant must be trapped into a material. In many instances, fossils are found in sediment. Layers of sediment will envelop the remains; this can continue for thousands of years. The actual remains that are found aren't the animal or plant at all. Instead, the remains begin to decay within the sediment. Minerals then replace the space that was once the remains. The mineral hardens and makes an impression of the animal or plant. What is left is what is known as a fossil.

Freezing and Mummification

Some of the most amazing fossils are of animals that have been frozen or are mummified. Animals found under freezing conditions and preserved completely are usually rare finds. Mummified animals are also rare, and are found in arid regions of the world.

Imprints

Imprints are the types of fossils where animals have left tracks of their movements in sediment. These usually include dinosaur and even human footprints.

Petrification

Petrification involves trees and not animals. When part of a tree falls and begins to die, the organic material will be converted into silica, which then becomes stone over time.

Amber

Another type of fossil occurs when an insect becomes trapped within amber. As time goes by, the amber will keep the remains of their insect in perfect condition, sometimes for millions of years.

Resources

• How Are Fossils Formed
• Fossils
• Amber