Dinosaur Tracks and Fossils

Materials

• plastic trays from frozen entrées
• modeling clay
• Plaster of Paris
• play dinosaurs or dinosaur skeletons
• 1 C measuring cups
• water
• brown tempera paint
• sand or potting soil

Background Information

Dinosaurs walking through clay near a lake left impressions of their feet including scales of their skin and prints of their toes. As the mud hardened, cracks around the tracks formed. Eventually the lake level rose and buried the tracks with sand and silt. Over time the sand hardened and became sandstone thus preserving the dinosaur tracks.

Activity

Give each child a ball of clay. The students will need to soften the clay by warming it with their hands and squishing it.
Pass out the plastic trays. Show the children how to press their clay into the tray to cover the bottom about 1⁄4 inch thick.

Children take a toy dinosaur and press its feet into the clay as if the dinosaur had taken several steps. They can repeat this with more than one dinosaur.

Mix the plaster 3 parts plaster to 1 part water. Mix until it is like a thick pancake mix.

Pour the plaster over the clay. Let it harden about an hour.

Help the children carefully remove the plaster from the tray. They have a fossil track! (The clay can be reused.) Paint with brown tempera that has a little sand or soil added to it.