- Bones and shells must be buried by sand or mud to become fossils.
So, making a fossil is a bit like making a sandwich.
- The bread is soft mud at the bottom of a pond, and the sandwich filling
is made of different creatures.
- Soft white bread
- Paper clips
- Other objects
- Place a piece of bread on a table - this is the mud at the bottom
of the pond.
- Place some of your creatures (paper clips, leaves, etc.) on the bottom
of the pond (the bread).
- More mud is swept into the pond and settles over the objects (add
another slice of bread)
- Repeat steps 1-3 a couple more times.
- SQUISH the sandwich with your hand. This is similar to sediment getting
squished by heavy sediment above it.
- Now pull apart the layers and look at how things are preserved.
Were some things fossilized in greater detail than others? Why?
Discuss: In what ways is this fossil sandwich not realistic?
Main Message: This exercise shows how fossil organisms and their impressions
are formed within layers of sediment. It also shows that some objects
are better preserved than others.
Connections: Activity 2 (about settling sediment),
and activity 5 (about finding fossils) will help
reveal what really happens.