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Mud Fossils - Activity for K-3 students (Allow 30-45 minutes)



  1. This activity calls for the students to observe real fossils. If you have none, you might borrow some from a local geologist or a serious amateur fossil collector. Geologist can be found at most colleges or universities, through various State and Federal government agencies, or through a number of engineering and environmental consulting firms. Fossil collectors can often be found at local gem and mineral shows or through local rock shops.
  2. This activity requires two class periods with 3-4 days in between to allow fossils to dry. Note: If you do not have any real fossils, go directly to item 2 of the Exploration Phase.
  3. Prior to item 2 of the Exploration Phase, the teacher should mix soil and water in the dishpan to make a thick mud mixture. Try this before the lesson to be sure you get the correct consistency.
  4. Emphasize that care is needed with the sharper objects and tools used to pick the fossils so that the students and those around do not get poked or hit by flying mud.


  1. You may wish to introduce this activity by having students observe real fossils.
  2. Ask students questions such as:
    1. How does a paleontologist recover fossils?
    2. How do you think these fossils were formed?
    3. What could we learn by observing fossils?
    4. Where are fossils found?
  3. Take students outside for this part if possible. Have each group of students number their margarine tubs. Then, have students place a layer of mud in the margarine tubs, more than half filling the tubs. Press the chosen material (leaves, bones, etc.) into the mud. Cover with 3-5 cm of mud. Let mud mixtures thoroughly dry in the sun (3-4 days).
  4. Give each group of students a filled margarine tub. Have students carefully break mud apart to find materials and imprints. Emphasize that they are trying to get the fossils out in the best possible condition.
  5. Display mud fossils.


  1. Ask the students the following questions:
    1. What are fossils?
    2. How do fossils get preserved?
    3. What problems are there in recovering fossils and prints from hardened mud? What would it be like to remove fossils from a rock?
    4. What are the best ways to remove fossils and prints without breaking them?


  1. Discuss with students how geologists use fossils in the interpretation of earth history and in the location of petroleum and other economic resources.