Making Plant Fossils

Students learned that scientists know about plants that lived long ago by studying the fossil, the remains or mark of a once living thing. First, plants died and were pressed into mud. Next, the plant rotted away. But the mud kept the form of the plant. Over time the mud hardened into rock. The flat imprint of the plant is seen when the rock cracks open. To help understand this concept, students made their own plant fossils today. We used Plaster of Paris and water to simulate mud. Then we pressed a plant part into the plaster. We waited for about 10-15 minutes (not 10 to 15 million years!) and then removed the plant. We had an imprint in the plaster--a plant fossil! This activity helped us see how scientists can tell what plants looked like millions of years ago.

Plant Fossils on PhotoPeach