Question: How are fossils formed?

Time Needed: 2-3 class periods


To determine the environmental factors necessary to create fossils.

To research the various methods of fossilization.

To identify what each method of fossilization can reveal about the once living organism.

Materials Needed: books, computers, fossil samples that demonstrate different processes of fossilization (Note: possible sources of fossil samples may include a trip to a museum, local college or university, or a geological site known for fossils)

Preparation: find relevant websites to help start students' searches (such as those listed on Links page) and fossil books


1. Break students up into small groups.

2. Assign each group a category of fossilization (Categories found from Berkeley site: http://www.ucmp.berkeley.edu/paleo/fossils/




Cast and Molds


Molecular Fossils



Drying and Dessication

Wax and Asphalt

Trace Fossils

Lesson Body:

Day 1: allow groups to use internet and library sources for the class period

Each group is responsible for answering the following questions about its particular category.

1. What is being fossilized in this particular process? Are certain organisms more susceptible to being fossilized this way? If so, why?

2. How does this process occur? What environmental factors favor this process?

3. What can we learn about the organism from looking at a fossil made from this process?

4. Find an example. Note something you find interesting about it.

Day 2: Each group will present what it has learned about its particular category. Students will note key points and write them down on a worksheet.

Either on Day 2 or 3 depending on how much time is available: Have fossil samples made by different processes ready at different stations set up around room. (These fossils do not have to represent all different processes, some of them can repeat if necessary.) Split students up into different small groups. Have each group use its members' knowledge and "Fossil Categories" worksheet to determine how each fossil was formed. Record answers in table.

Wrap-Up: Go over the fossil samples as a class and see how much the students agree or disagree on the answers.


National Standards Addressed:

This lesson falls under the category of Earth Science for grades 5-8. The students will be learning about the processes of fossilization and what the fossils can tell us about the organism and the surrounding enviroment.


Link to Fossilization Page