Lesson Title: How Do Fossils Form? 
by:  Alba Ramirez, Debra Zinicola
Grade Level:  Elementary

Goals:  To demonstrate how fossils are created over time and how they take the shape of objects. 

Learning Objectives: Students will:
create models of fossils from Plaster of Paris and water.
observe how the plaster takes the shape of an object.
communicate how fossils are formed through changes in their surroundings. 

NJ Science Standards: 5.10: All students will gain an understanding of the structure, dynamics, and geophysical systems of the earth. #2 Investigate materials that make up the earth, including rocks, minerals, soils, and fossils, and how they are formed. 

Materials:
box of Plaster of Paris
1 gallon of water
20 spoons
20 cups
20 balls of modeling clays
assortment of seashells
paper towels
http://www.scsc.k12.ar.us/TuttS/fossil_formation.htm

http://www.zoomschool.com/subjects/dinosaurs/dinofossils/Fossilhow.html – both sites explain with pictures how fossils are formed.  

Procedure:
Introduction:

I asked the students if they have ever gone to a museum and saw fossils. What kind of fossil (footprint, leaf, etc.)?  I asked them how long they thought it took for a fossil to form.  How are fossils formed? What can fossils tell us about earth’s history? 

Exploration:

Distribute modeling clay to each student. They will have to first mold a ball, then create a small bowl with the clay. Explain to them that they will pick out a seashell and press it onto the clay, not too firmly and press the side that they would want to see imprinted (mold). Take it out.

Hand out the box of seashells and tell them to pick one and press it onto the clay.

Pass out cups filled with about 2 spoonful of plaster to each student. 

I will ask for each of the students to come up to get some water after they are done with the clay. 

Mix the water and plaster until you get a pasty look.

Pour the plaster onto the clay bowl making sure it does not spill over. 

I will take about an hour for it to dry.

Make sure it is completely dry before you gently peel the clay off. The end result should be an imprint (cast) of a shell.  To extend the lesson, students may color the fossil with paint and write their names on it. Clay can be re-used. 

Student Product:

Application:

I will pass out the worksheet that I created using a website. Students can work together at classroom computers or complete the activity in the lab. The completed fossil model is also an artifact that can be used as a creative writing prompt.

Assessment: Students will answer questions in their journals in addition to describing their own fossil and what it tells us about that creature. Students will orally explain how fossils are formed.

Reflection:
I started with a little background on fossils and what different types of fossils are found.  I told them how helpful it is for scientists who want to learn more about the evolution of animals and plants on the earth. I should have read up more on fossils, and find ways that I can relate it to children. The students were very excited about mixing and pouring the plaster.  They also were excited to choose from the array of seashells that would turn into their own fossil.  Some students picked seashells that will easily come out, but others picked ones that were going to be difficult to see as an imprint.  I let them pick and see the results for themselves.  Many of the students were also curious about how long it was going to take for the plaster to harden.  I told them it was going to take a much shorter amount of time than the fossils found in the Earth.  The students were very cooperative, much to the surprise of the teacher. I just had problems relating fossils to them at the beginning of the lesson.  But they were very excited because they were doing a lesson on dinosaurs and fossils. Websites are excellent and appropriate for children to read and understand. They enjoyed working on the computers with this assignment.

Types of Fossils 

http://www.zoomschool.com/subjects/dinosaurs/dinofossils/Fossiltypes.html

Click on the hyperlink to find a site about Fossils. Read the page and answer the following questions in your journal.

1)       What are the 4 types of fossils?

2)       What 2 types of fossils did you make today?

3)       Who discovered T-rex’s skin?

4)       What can fossil footprints tell us about the dinosaurs?

5)       What are Gizzard Rocks?

6)       What kind of fossil would you most like to find and why?