FOSSILSBy: Colby Lacks

How fossils are useful

Without such fossils, scientists would know very little about the history of life on earth.

The answers we get from rocks often cause us to ask more questions!

What all fossils are in

Fossils are in all types of rocks. When organisms die, the soft, fleshy

parts of their bodies decompose, leaving only the hard parts.

There are such things as Fossils in Amber, Frozen fossils, and Fossils in Tar.

What Fossils are

Fossils are the remains or traces of plants and animals that have been preserved in sedimentary rock.

Fossils have given us enormous amounts of information about ancient life-forms and how they in the oceans.

Where fossils come from

Most fossils come from animals that lived in the oceans.

The fossils some rocks contain also provide clues about life-forms that lived billions of years ago, long before dinosaurs walked the earth.

Fossils

Fossils (from Latin fossus, literally "having been dug up") are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record. The study of fossils across geological time, how they were formed, and the evolutionary relationships between taxa (phylogeny) are some of the most important functions of the science of paleontology. Such a preserved specimen is called a "fossil" if it is older than some minimum age, most often the arbitrary date of 10,000 years ago.[1] Hence

Dinosaur

Scientists have found dinosaur fossils on every continent. Most of these sites are in the United States and Europe.

Scientists dig very carefully using chisels to free the fossils from the rock they are trapped in. They take lots of notes to describe the fossils and where they are found. Then they take the bones to a laboratory and analyze them. They try to put the bones back together like a puzzle. Sometimes this part is easy, other times it's very difficult.

Once they know how the bones fit together, a scientific artist sketches the bones and adds muscles and skin.

How fossils differ

Most fossils are heavy and look like rocks. They’re also a light brown or dark white color.

Their shapes are different, however. Fossils are shaped like whatever the original objects were. Some are shaped like leaves, some are shaped like paw prints, some are shaped like bones. Fossils’ sizes are also different for the same reason. Some fossils belonged to large dinosaurs. Others belonged to tiny insects.

How fossils form

When an animal or plant dies, usually the remains are eaten or decompose.  On occasion though, they get buried by mud or sediment, and in the right conditions, they harden into fossils. 

The bones or original material decay, and water or other things seep into the impression left by the original material. This water and minerals continue to dissolve the original material, replacing it, and then they harden over time.

Once the fossil is formed, it’s usually heavy and feels more like a rock. It’s also colored like a rock because that’s what it really is! It just has a shape of something that was alive a long time ago, and that’s what makes it a fossil.

 

Animal fossils

Animal fossils are often bones that have been turned to rock.  Sometimes part of the flesh is preserved, but most of the time only skeletons remain.  Because of this, it is more difficult to find fossils of invertebrates. (Invertebrates are animals that don’t have bones.)

We have discovered several types of animal fossils, including bones, skin, teeth, claws, eggs, nests, muscles, and organs.

We have also found lots of fossils of footprints, which tell us how much animals and dinosaurs weighed and how they might have walked.

Insect fossils

Insect fossils form in the same way as normal fossils, but the exoskeleton is usually the only thing that is left.  One special type of insect fossil is when it is preserved in amber.  Amber is tree sap that oozed over and covered the insect, then hardened.