Stories in stone
A fossil is what is left of a plant or animal that lived long ago, kept in rock. Find out how a bone can turn into stone, meet the young fossil hunter Mary Anning, and make your own fossil prints.
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A fossil is what is left of a plant or an animal that lived long ago, kept in rock. Most fossils are very, very old.[3][5]
Usually only the hard parts become fossils: bones, teeth, shells and wood. Soft parts, like skin, rot away.[1][4]
How does a bone turn into stone? An animal dies and is quickly covered by mud or sand. More and more layers pile on top and slowly turn into rock. Water seeps into the bones and leaves tiny bits of minerals behind, so the bones turn to stone. This takes thousands or even millions of years![1]
Footprints and burrows can become fossils too. They are called trace fossils. Even fossil poo has been found![5][1]
Most plants and animals never become fossils. They rot away and leave nothing behind.[1]
Mary Anning lived in Lyme Regis, by the sea in England, more than 200 years ago. When she was 12, her brother found a huge skull in the rocks. Mary dug out the rest of the skeleton: a giant sea creature called an ichthyosaur.[2]
Try it: Make fossil prints
You need
- A ball of play dough or modelling clay for each child
- Some shells, leaves or twigs
- A clean toy animal with feet
- A rolling pin or a smooth bottle
- A magnifying glass
Safety
Do not put play dough in your mouth. Use smooth shells without sharp edges. Wash hands afterwards.
What to do
- Roll the play dough flat and smooth.
- Press a shell or a leaf firmly into the dough, then lift it out carefully.
- Walk the toy animal across another part of the dough to make footprints.
- Look with the magnifying glass. What shape is left behind?
- Swap with a friend. Can they guess what made each print?
Play: Fossil or not?
Is it a fossil? Tap the right group.
Your best score is kept only on this device. Nothing is sent anywhere.
Quiz
Other ages: Ages 10–11 · Ages 15–16