tell of long ago. fossils are animals or plants that lived a very long time ago. after they died,...

Tell of Long Ago

Fossils are animals or plants that lived a very

long time ago.After they died, they

turned to stone.

How do animals and plants become fossils when they die?

Most don’t…they just rot and disappear, often in swampy forest soil called peat.

Sometimes leaves fall in the peat. The leaf may rot away, but the mark of its

shape is left.

The peat with the leaf hardens into a rock, called coal. Coal is a fossil too.

Sometimes animals die and only their bones are left, covered in

mud.

Thousands of years go by, the mud piles up in layers and the weight of the mud presses down on the bones. The mud turns to rock.

As that happens, ground water seeps through the changing layers

of mud.

Minerals are dissolved in the water.

The water seeps into all the tiny holes in the fish bones.

After a very long time the bones turn to stone and become a fossil.

Some fossils are actual parts of plants or animals that have turned to stone.

Sometimes a fossil is only an imprint of a plant or an animal.

Not all fossils are found in stone.

Some are found in the frozen ground of the Arctic, like the bones of the ancient mammoth.

Millions of years ago, a fly was caught in the sticky sap of a tree.

The sap hardened and became a fossil known as amber. The fly was preserved in the amber.

We can learn many things from studying fossils.

Fossils tell us

about the

past.

More About Fossils…(right-click to open hyperlink)

• How fossils are made• What is a fossil?• What makes a fossil

movie• Fossil Horses in Cybe

rspace• Introduction to the

Annelida

Open Court Reading 2002, Level 2, Unit 4Created by Carol Potter, 2005