Fossils are formed in several different ways. Sometimes actual animal and plant remains are trapped in a substance and preserved, as are ants in amber (fossilized tree sap) and woolly mammoths in ice.
Woolly mammoths lived during the last ice age. Although they are now extinct, people sometimes find their frozen bodies in far northern latitudes.
Sometimes minerals may replace the remains, leaving a hard replica, as happens when petrified wood forms. Trace fossils are imprints of plants and creatures on surrounding material, such as footprints that have hardened into rock. The original remains are gone, but you can see where the fossil was: a three-dimensional imprint of past life.
The coelacanth, a rare fish once thought to be extinct, is called a "living fossil" because it bears such striking Similarity to fossils that formed millions of years ago.
You can build models of fossils using common materials. If you live or travel to the right geographic area, you can find and collect real fossils, or you can purchase fossils from some museum or fossil stores.
- Nut, seed, or other natural object
- Artist's paintbrushes
- Floor wax
- Plaster of paris
- Shallow dish
- Silicone caulking gel
- Fossil field guide
To Make the Mold
- Select a natural object from which to make a model trace fossil, such as a nut or a seed.
- Clean the surface of the object with a paintbrush.
- Use a paintbrush to coat the object with floor wax, to make later extraction easy.
- Mix some plaster of paris according to the package instructions.
- Put the plaster into a shallow dish and rest the object in it. To make extraction easy, do not immerse the object completely.
- Allow the plaster to harden overnight.
- Extract the object from the plaster. You have made a mold of the object.
To Make the Model Fossil
- Fill the mold with silicone gel, and allow the gel to harden.
- Extract the hardened gel gently with your fingers. This is the cast and should look much like your original object. Paint the cast for display.
Impressions are the images left by plant or animal remains after they have been pressed against sediment such as clay or soil. If remnants of the original organism remain, the remains are called a compression.
Animals Dazzlers: The World of Animal Fossils by Collard B. Sneed III (Danbury, Conn.: Franklin Watts, 1999).
Death Trap: The Story of the La Brea Tar Pits by Sharon Elaine Thompson (Minneapolis: Lerner, 1994).
Fossils (Dorling Kindersley Pocket series) by Douglas Palmer (New York: Dorling Kindersley, 1996).
If You Are a Hunter of Fossils by Byrd Baylor (New York: Aladdin Paperbacks, 1984).
Is There a Dinosaur in Your Backyard? The World's Most Fascinating Fossils, Rocks, and Minerals by Spencer Christian and Antonia Felix (New York: John Wiley & Sons, 1998).
Fossils–Behind the Scenes at the Royal Ontario Museum:
Fossils–Windows to the Past:
You can successfully find fossils in certain geographic areas. Get a fossil field guide from a bookstore or library to conduct your search. The following are just a few examples of fruitful fossil locations:
- Portland, Connecticut: Dinosaur footprints in brownstone.
- Deschutes River, Oregon: Petrified wood along the riverbanks.
- San Pedro, California: Head of a Miocene baleen whale found in stone.
- Cook County, Illinois: Sea-dwelling creatures fossilized in Niagara limestone.
- The American Museum of Natural History in New York, of course! Museums are the best place of all to find fossils.
You can bring your materials to these locations and make plaster molds to take imprints of fossils in the stone. Of course, you should always have permission from landowners before entering their property or conducting archaeological work there. You are generally not allowed to take fossils from public lands.
Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state’s handbook of Science Safety.