Fossil Fun Category: Geology Type: Class Experiment, 1 hour Materials: 1 1 1 1 Block of clay Small paper cups Plastic cup Spoon Plastic insect or shell Tray Water Plaster of Paris Video: http://youtu.be/m4f_YjYADYw How To: Take a small handful of clay. This will represent the ground. Fill a paper cup approximately 1/3 full with clay. Press it into the cup using your fingers. Flatten and smooth the top of the clay. © 2013 Mission Science Workshop. All Rights Reserved worldwide. When linking to or using MSW content, images, or videos, credit MUST be included. Choose an object to fossilize that will fit in the cup. Press the object into the clay. Remove the object and make sure that a good imprint has been made in the clay. To make the plaster, pour 2 small paper cups of Plaster of Paris powder into a plastic cup. Pour one small paper cup of water into the plastic cup with the Plaster of Paris powder. Mix well. © 2013 Mission Science Workshop. All Rights Reserved worldwide. When linking to or using MSW content, images, or videos, credit MUST be included. Pour the plaster over the clay in the dixie cups. Fill the cup approximately ¾ full. Let the plaster harden for 45 minutes to 1 hour. Tear the dixie cup open at the side seam and remove it from the outside of the clay/plaster. Separate the plaster from the clay to reveal the fossil. Fine Points: →
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Larger cups can be used to make bigger fossils. The amount of plaster used above is enough for 3 fossils made in small paper cups. The clay can be reused for more fossils. A toothbrush can be used to clean clay off the fossils, just as fossil hunters do with real fossils. Use a lighter colored clay if you want to avoid staining the fossils. Once cleaned, the fossils can be painted (though real fossil hunters would not generally do this!). Concepts Involved: •
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In the distant past, some animals died in places where their bodies became engulfed in mud or clay. With time this material hardened to preserve the form of their bodies. Body fossils are the preserved remains of a plant or animal's body, or the preserved form of a plant or animal’s body. Focus Questions: 1. Where do you think fossils can be found? 2. How do you think fossils are formed? 3. Why do you think fossils are important? © 2013 Mission Science Workshop. All Rights Reserved worldwide. When linking to or using MSW content, images, or videos, credit MUST be included. Elaboration: When children think about fossils they often think of dinosaur bones, but fossils come in all shapes and sizes. The word fossil comes from the Latin word fossus, which means “having been dug up”. Fossils are the preserved remains of plants and animals from the past. Fossils that have been found in rocks represent the ancestors of plants and animals that are alive today. There are two main types of fossils, body fossils and trace fossils. Body fossils are the preserved remains of a plant or animal's body. Trace fossils are the remains of the activity of an animal, such as footprints, egg shells and nests. The branch of biology that studies forms of life that existed in former geologic periods, primarily by studying fossils is called paleontology. Fossils are formed in a number of different ways, and each process depends on both the organism and external conditions. The fossils we made in this experiment are called casts or molds. The remains of the organism are completely dissolved or destroyed, and the organism-­‐shaped hole in the rock is called an external mold. If this hole is later filled with other minerals, it is a cast. Another way fossils are formed is through mineral replacement. This type of fossil is formed when animals that died were buried quickly, e.g. sinking in mud, falling to the bottom of the ocean. The softer parts of the animal decayed quickly, and over time more and more sediment covered the remains. The parts of the animals that didn't rot (normally the bones and teeth) were encased in the newly formed sediment. Over a long time the chemicals in the buried animals bodies changed. As the bone slowly decayed, water that contained minerals seeped into the bone and replaced the chemicals in the bone with rock-­‐like minerals. This process of fossilization involves the dissolving and replacement of the object’s original minerals with other minerals. Being embedded in amber is another way to be fossilized. Amber is formed from hardened tree sap, so the types of fossils usually found in amber are parts of plants or insects. Petrification is another way. This process can preserve hard and soft parts of plants or animals, and slowly replace organic material with silica, calcite or pyrite, forming a rock-­‐like fossil. Wood is often found petrified. Volcanic ash covered the wood and prevented it from rotting. As rainwater fell on the ash over the years it would seep through the ash into the wood. The replacement of minerals makes a replica of the wood. Links to k-­‐12 CA Content Standards: Grades k-­‐8 Standard Set Investigation and Experimentation: Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other strands, students should develop their own questions and perform investigations. Grades k-­‐12 Mathematical Reasoning: 1.0 Students make decisions about how to approach problems: 1.1 Analyze problems by identifying relationships, distinguishing relevant from irrelevant information, sequencing and prioritizing information, and observing patterns. 1.2 Determine when and how to break a problem into simpler parts. 2.0 Students use strategies, skills, and concepts in finding solutions: 1.1 Use estimation to verify the reasonableness of calculated results. 1.2 2.2 Apply strategies and results from simpler problems to more complex problems. © 2013 Mission Science Workshop. All Rights Reserved worldwide. When linking to or using MSW content, images, or videos, credit MUST be included. 1.3 Use a variety of methods, such as words, numbers, symbols, charts, graphs, tables, diagrams, and models, to explain mathematical reasoning. 2.5 Indicate the relative advantages of exact and approximate solutions to problems and give answers to a specified degree of accuracy. 3.0 Students move beyond a particular problem by generalizing to other situations: 3.1 Evaluate the reasonableness of the solution in the context of the original situation. 3.2 Note the method of deriving the solution and demonstrate a conceptual understanding of the derivation by solving similar problems. 3.3 Develop generalizations of the results obtained and apply them in other circumstances. Grade 2 Standard Set 3. Earth Sciences Earth is made of materials that have distinct properties and provide resources for human activities. As a basis for understanding this concept: 3.d. Students know that fossils provide evidence about the plants and animals that lived long ago and that scientists learn about the past history of Earth by studying fossils. Grade 7 Standard Set 3. Evolution Biological evolution accounts for the diversity of species developed through gradual processes over many generations. As a basis for understanding this concept: 3.c. Students know how independent lines of evidence from geology, fossils, and comparative anatomy provide the bases for the theory of evolution. 3.d. Students know how to construct a simple branching diagram to classify living groups of organisms by shared derived characteristics and how to expand the diagram to include fossil organisms. Grade 7 Standard Set 4. Earth and Life History (Earth Sciences) Evidence from rocks allows us to understand the evolution of life on Earth. As a basis for understanding this concept: 4.e. Students know fossils provide evidence of how life and environmental conditions have changed. © 2013 Mission Science Workshop. All Rights Reserved worldwide. When linking to or using MSW content, images, or videos, credit MUST be included.