Materials required: small paper plates (although cut-off cups work, as well), plaster of paris, vaseline or baby oil, and small plastic toys.
Preparation time is about 10 minutes.
This activity is appropriate for all ages.
An entire afternoon visit (1 hour) will be a good amount of time for this activity.

    While someone mixes up the plaster of paris, the rest of the WOODS people should talk with the kids about fossils - how they're made, what leaves them (ie HARD things like bones or scales), and why they are made at all. A good idea is to bring in some pictures of fossils or, if you're really ambitious, some actual fossils to pass around.
    Have everyone select a toy and coat it with vaseline or baby oil (so it will come out after the fossil is made). Dish out a plate-full of plaster of paris (it doesn't have to be too deep) for each kid to press their toy into, and watch a fossil form!
*Note* ~ fast drying plaster of paris works best, but you ahve to work QUICKLY!!