Impressions in clay; Fossils Lesson

 

Introduction:

“What are fossils? How are fossils made? Has anyone seen a fossil before? What kind? Where? We are going to be talking about the La Brea Tar Pits in Los Angeles, California. These tar pits hold many fossils of animals that have gotten caught in the tar”.

 

Purpose:

To illustrate how impressions form, and how hard or easy it is for organisms to leave impressions, students will make impressions of different objects in clay. In nature, muddy or clayey sediments are the best sediments for leaving impressions, so using clay in the classroom is a good model for nature 

 

Grade level: K-8

 

Time: 15-30 minutes

 

Materials:

• Different types of objects to make impressions.

Examples: Leaves, Shells, Bones, Animal Teeth, Toy Dinosaurs. 

• Air-drying clay to make impression on.

                         Enough for each student to have a palm sized ball of clay

 

Procedure:

1. Have students get into groups of 3 or 5 (or whatever works best for your class).

2. Hand each student a palm-sized ball of clay. Explain to students that the clay will air-dry when left alone.

3. Have students flatten the ball of clay, like a pancake to represent a tar pit. 

4. Have students chose their object they want to fossilized.

5. Show students how to press the object into the clay.

6. Pull object out of clay and show imprint.

7. Explain introduction again here if necessary.

8. Let students try activity. They can do it as many times as needed/want, as long as time permits.

9. Have students look at their classmates fossil impressions to see the different kinds.

10. Then, have students tell a story about how the object got fossilized of their partners (or their own) impression to their partner.

 

“Which type of object left the best impressions? How about the ones you cannot really see?”

 

Emphasis during activity:

“Fossils are any evidence of ancient life preserved (usually) in stone. Many fossils are impressions of ancient life, rather than any preserved part of the actual organism. Impressions of hard parts are more common than soft parts, but impressions of soft parts such as skin and scales have been preserved as fossils in rock. Fossil tracks are also impressions” (Impressions in clay, Educational Resources for K-16).

 

Closure:

"So, can someone tell me what a fossil imprint is? How is it made?"

 

Variations and extentions:

1.Have students collect their own objects (from home or outside!). Size depends on size of clay used for impressions.

2. Field trip to a fossil museum! Or the La Brea Tar Pits Museum!

3. Homemade Tar Pit

Made from Cornstarch, food coloring (black), and water. (Becareful of students with an allergy to cornstarch). 

4. Play a video about the La Brea Tar Pits during the project time.

 

Based on the lesson plan: "Impression in Clay"

We used basically the same lesson plan. Since we are talking about fossils the lesson plan really did not need to be modified for our region. We will have to students work in groups and each person/group have a different object to imprint as a fossil, instead of each student getting 5 different objects. The students will then look at their classmates fossils and see the differences in the impressions. We made a model tar pit for the begining of the avtivity with cornstarch. We decided to play a video during the time when students are working on their imprints. We also will not have students be working on a worksheet during this time.