Fossils are the remains or marks of plants and animals that lived a very long time ago. They are usually found in rocks and stones. Fossils are important because they tell us a story about things that lived on the earth before us.
What Things Become Fossils?
Animals and plants become fossils. So do nests, eggs, footprints and even animal droppings!
How are Fossils Made?
Fossils are made from the hard parts of plants and animals, such as:-bark, seed cases, bones and teeth. These parts do not easily rot away after plants and animals die. Fossils take millions of years to form.
Turning to Stone
For example: -A star fish dies.-The soft parts of its body rot away quickly. The harder parts slowly get covered by mud. After millions of years, the star fish is deep in the ground. The mud around it is crushed by the land on top and-turned to stone. So are the remains of the star fish. Millions of years later, the stone gets worn away and the- fossil can be seen.
Kinds of fossils
Body Fossils - include the remains of organisms that were once living. Usually only the hard parts of animals like shells and teeth and bones become fossilized. However, feathers, fur, and skin have also been found.
Trace Fossils- are the signs that organisms were once present. Trace fossils can be tracks, footprints, trails, burrows, eggs, nests, leaf impressions, and feces. Take a peek at these Images of trace fossils
There are also fossil plants
Where are fossils found?
Fossils may be found almost anywhere sedimentary rocks are exposed. Sedimentary rocks are rocks that formed when layers of sediment such as clay, mud, silt, or sand hardened over millions of years. These types of sediments settle down in lakes, swamps and oceans. This is one of the reasons why most fossils are the remains of animals who lived in or near the water.
What do fossils tell us?
Rock layers can tell us...