Fossils are like leaving a footprint on the earth. In some cases, they are actual footprints from millions of years ago. Have children leave their own unique dinosaur footprints using their hands. Encourage them to shape their hands how they imagine a dinosaur footprint would look. Dip the hand in washable ink and help the preschooler make a footprint on a piece of paper. As an alternative, the child can leave his mark on a flattened piece of modeling clay. Heat the clay in the oven or otherwise dry it overnight so it hardens and the footprint becomes permanent.
Turn preschoolers into paleontologists by uncovering fossils in the classroom. For this project you will need a shallow tray of sand or rice, thin cardboard or cardstock paper and a picture of a dinosaur. Glue the picture of a dinosaur to the cardboard. Allow it to dry and cut it into six pieces. Bury the pieces in the tray of sand or rice. Let the children dig for dinosaur fossils. Encourage them to collect the pieces they find and try to assemble them to make one dinosaur. Then ask them to identify the type of dinosaur. This is what scientists have to do -- put together pieces of what they find to identify the dinosaur.
Hide clean chicken or turkey bones in a shallow tray of sand or rice for children to find using only their hands and paint brushes. Discuss why paleontologists use paintbrushes to keep from damaging the bones. Ask them to take notes on the bone like a real scientist. They should draw a picture of the bone, take measurements and make notes on what else they observe.
Help preschoolers understand how fossils are made by making their own. For this craft, you will need a small tray with sides about ½ to 1 inch tall for each child. Smaller ice cream container lids work well for this project, as long as they are clean. You will also need wet sand, Plaster of Paris and small plastic dinosaurs. Put sand in the trays and wet the sand with water until it is easily shaped. Help the children push the plastic dinosaurs into the sand, then remove them to see the shape of the dinosaurs left behind. Apply Plaster of Paris to their fossils and allow them to dry overnight.