Experience an archeological dig, right in your own classroom! Students create fossils the way that nature does - by making impressions and filling them. Students will learn a simple plaster-casting method used by both artists and scientists. Then, the fun really begins as the fossils are "unearthed"! The detail is surprisingly accurate and finished pieces look a lot like the real thing.

Grade Levels

K–8

Lesson Objectives

• Students will learn how fossils are created by reproducing the process of creating an impression and filling it with a hardening material
• Students will discover a simple mold-making and casting process using classroom-safe materials
• Students will employ some of the same processes used by archeologist when uncovering centuries-old fossils

Preparation

Save chicken or fish bones, coarse leaves, etc. Prepare by removing as much of the meat as possible and drying well in an oven or window. Bones can also be boiled, but still need to dry in an oven or outdoor sunlight.

Procedure

1. Fill a shoe box with damp sand, about 3" deep
2. Push the bones into the packed sand and carefully remove, leaving a negative impression. Very young children can leave objects in the sand, as it will be difficult for them to remove and fill without disturbing the impression.
3. Mix the plaster. It helps to have students work in pairs. Using a bowl or plastic container, measure 3 cups of dry plaster and add 1 to 1-1/2 cups of water. Stir until mixture is pancake batter (pourable) consistency.
4. Pour into shoebox immediately (one shoebox at a time). Pour from one end of the box to the other. Do not dump in middle and try to spread, this disturbs the impressions.
5. If desired, place an opened paper clip in the wet plaster for use as a hanger once the cast is dry.
6. Allow to set for about 2 hours. Check frequently to see how plaster changes from wet and cold, to warm, then back to cold. Do not remove until totally dry - 24 hours. It is difficult to wait but damage can occur if removed too soon.
7. Tear sides from the shoe box. Use fingers to dig away sand from the sides.
8. Turn plaster right side up and use brush to remove sand from the cast. As it is exposed to the air, it will be easier to remove sand.

Topics for Discussion

1. Fossils are often the only clues we have to the lifestyles of ancient cultures. Try to plan casting as if you were going to communicate something to persons thousands of years in the future. What would you want them to know about your life and surroundings?
2. Have students exchange casting and “unearth” a project that is not their own. Then, have them discuss their findings and hypothesize about the objects they have discovered - what are they? what is their significance?
3. Discuss the fossil the students have created and it's aesthetic qualities. Why would some people consider this a work of art? Why would other people not consider fossils to be art? Does art have to be something man-made?

National Standards

Content Standard #1 — Understanding and applying media, techniques and processes

K-4 Students use different media, techniques and processes to communicate ideas, experiences and stories

5-8 Students intentionally take advantage of the qualities and characteristics of art media, techniques and processes to enhance communication of their experiences and ideas

Content Standard #4 — Understanding the visual arts in relation to history and culture

K-4 Students know that the visual arts have both a history and specific relationship to various cultures

5-8 Students analyze, describe and demonstrate how factors of time and place (such as climate, resources, ideas and technology) influence visual characteristics that give meaning and value to a work of art

Content Standard #6 — Making connections between visual arts and other disciplines

K-4 Students identify connections between the visual arts and other disciplines in the curriculum

5-8 Students describe ways in which the principles and subject matter of other disciplines taught in the school are interrelated with the visual arts