Condensing Millions of years into Just 1 or 2 Days

There is a method to recreate the look of a fossil and in the process of making it, help kids understand the actual process of how real fossils are formed.

You will need: soil (preferably with a high clay content to avoid crumbling), water, container for mixing, spoon or stirring device, item to be fossilized (leaf, shell, snail, etc.), wax paper, cookie sheet, jarring wax (optional)

1. Fill your mixing container halfway with soil and add water until you have a thick mudlike consistency which is easy to mold.
   
2. Insert the item to be "fossilized" into the mixture and cover with the mud.
   
3. Place the wax paper on a cookie sheet.
   
4. Form a tight cocoon of mud tight around the would be "fossil" and place it on top of the wax paper.
   
5. Leave somewhere dry, in the sun preferably for 1 or 2 days. If you live in a very humid climate, place it in a low oven for 2 hours.
   
6. Once the mud cocoon is dry, carefully pry it open, you can carve out a groove with a box knife to make it easier, and separate the two halves.
   
7. You will now have a negative imprint on hardened soil of the object.
   

You could stop here and explain how some fossils that are discovered form in this way, as negative imprints left on soil, that over time hardens, like our example, but longer into rock.

You could also continue to exemplify the formation of petrified solid fossils.

To do that, melt some jarring wax, and pour over the negative impression left on the dry mud.

Let it dry, then remove the mud around the hardened wax.

You can now explain how sometimes when creatures die, they fall in mud which covers them just like you did, then over time, minerals fill this void in the impression and literally turns the creature to rock, just like you turned your fossil into to wax.

Have fun, it is a good educational activity.

Tough dryish dough works great.

Normal plain flour with water and a teaspoon of vegetable oil - kneed until you get a firm dough mix. The dough can be molded or cut, even marked with veins for leaves :)

Once you have the shape you want BAKE on low ( about 80C ) for about 30 mins to hour ( time depends on how 'wet' your original dough is )

You are left with hard shapes that can be painted or buried or whatever.

The mix of ingredients really depends on the size of the batch you are making.

Hope this suggestion helps, I'm sure you'll get lots of ideas :)

Short of burying a bone for a few thousand years, I would recommend paper mache. You can get the look you want, you can get the shape you want, you can get the color you want.. Pretty straight forward.

Here is a writeup with a few recipes: http://www.buzzle.com/articles/how-to-make-paper-mache.html

Video too: