OUTREACH : 50-min. HANDS-ON WORKSHOPS : The Fossil Record

We’ll take a look at actual fossils and find clues hidden within that will help us learn something about life millions of years ago. Students will get to invent their own prehistoric animals, follow along in the story of fossilization, and learn about our planet’s various biologic and geologic processes.

Michigan Grade Level Content Expectations, Science, 2007

• Recognize and describe different types of earth materials. (E.SE.03.13)
• Identify and describe natural causes of change in the Earth’s surface. (E.SE.03.22)
• Explain how fossils provide evidence of the history of the earth. (E.ST.04.31)
• Compare and contrast life forms found in fossils and organisms that exist today. (E.ST.04.32)
• Describe how fossils provide evidence about how living thigns and environmental conditions have changed. (L.EV.05.13)

The Fossil Record Pre-visit Vocabulary

Carbon: A non-metallic, naturally occurring element essential to the structure of all organic compounds.

Carnivore: An animal that eats only other animals.

Fossil: Any trace of an organism from a previous geological era.

Fossilization: The process by which all the organic compounds in an organism are replaced with minerals.

Geological Time: A measure of time used to describe the formation of the earth.

Herbivore: An animal that eats only non-animals.

Omnivore: An animal that eats both animals and non-animals.

Organic Compounds: Chemicals derived from organisms and containing carbon.

The Fossil Record Post-visit Activity

Post-visit activities provide your students with an opportunity to review workshop-presented concepts and introduce related subjects. Below you will find a classroom extension activity and a list of suggested resources for further exploration. We hope that you enjoyed our Outreach Hands-On Workshop and we look forward to visiting your students again!

Hands-on Activity: Make a Fossil

Materials

• 1 or 2 small paper cups per student (bathroom cups work well)
• Modeling clay or moist sand
• Plaster of Paris
• Small re-sealable plastic bags
• Small items (shells, marbles, etc.)
• Scissors
  

Procedure

1. To pre-prep the Plaster, place 4 spoons of powder into a small re-sealable plastic bags. (Attention! Plaster of Paris can be dangerous to inhale.) Make enough for 1 bag per student.
2. Have each participant fill their paper cup about ½ ways with clay or moist sand. (Modeling clay usually works much better than sand. If you have to use sand, pre-moisten it so that it holds its shape when you press your finger into it.)
3. Carefully press your object into the clay or sand to make an impression. Carefully remove it. If you don’t see an impression, smooth over the clay and try again. If you use sand, make sure it is not too wet or too dry, otherwise it won’t hold the impression.
4. Add one spoon of water to your plastic bag and mix it into the plaster by massaging the outside of the bag. Continue to add a small amount of water to the plaster until it is about the consistency of pancake batter.
5. Cut the corner off the bag and carefully squeeze the plaster into your cup.
6. Let the plaster settle overnight.
7. Carefully rip the paper away from the plaster and lift the solid chunk off of the clay. You can reuse the clay without any trouble.
   

Discussion

What you have just made is a mold or a cast fossil. The plaster filled in the depression and took the shape of your original object. A variation of this experiment can be done if you leave the original object poking out of the clay or sand with the “interesting” side up. Before you pour the plaster over this, it is a good idea to spray it with butter (or substitute). This will help you get the object out of the plaster smoothly. After your plaster dries, peal away the paper cup and you’ll have an impression fossil.

The fossils that you’ve made took about a day to form. In real life, the time involved is over 10,000 years and the liklihood of a fossil forming is very rare. Encourage a discussion about the meaning of “geologic time” and have students construct a geologic time scale to display in your classroom.

Suggested Resources

Books

DK Publishing. Fossil. DK Children. 2004.
Aliki. Fossils Tell of Long Ago. Harper Trophy. 1990.
Perrault, Chris. The Best Book of Fossils, Rocks and Minerals. Kingfisher. 2000.
Blobaum, Cindy and Michael Kline. Geology Rocks!: 50 Hands-On Activities to Explore the Earth. Williamson Publishing Company. 1999.

Internet

Fossil Formation
Geologic Time Scale
The Virtual Fossil Museum