You can use bread, gummy animal candies and a little pressure to mimic the effects of fossils hidden in sedimentary layers. Layer three slices of bread on a paper plate. Arrange a few gummy candies between the slices of bread. Wrap all three pieces in a paper towel. Rest several heavy books on top of the dinosaur bread and apply pressure. Leave the books on the bread overnight. The next day, ask the children to predict what the gummies and bread will look like. Have them remove the books and paper towel from the bread and examine the effects of time and pressure on the gummy animals.
Use clay or modeling dough to create your own fossils. Flatten the clay then use an upside-down glass to cut it into circles. Press leaves, fern fronds, sea shells and small plastic insects into the clay rounds. Remove each object from the clay after a good impression is made and allow the clay to dry.
Using wire to represent the skeleton and modeling clay to fill in the soft parts, you can learn about dinosaur anatomy by building your own dinosaur. Use a picture of the dinosaur skeleton as a guide to form the skeleton. This part of the project can be as detailed as you like, tailored to the children's ages. Apply the clay to the skeleton and shape it as necessary.
Re-create an archeological dig with sand, chicken bones and a shallow plastic pan. Strip and clean chicken bones then soak them in a solution of water and chlorine bleach for a few minutes. Allow them to dry. Fill the pan with sand and enough water to make the sand packable. Position the bones within the sand and pat it down to eliminate air pockets. Give the children small hand shovels and paintbrushes so they can discover their own "dinosaurs."