I have made fossils with grade ones before as part of a dinosaur themed
unit. I do like the ones I had done previously with objects cast in plaster
(see them HERE) However, they were quite tricky. Then I saw this simple but effective fossil idea from Gail at That Artist Woman.
I had the students create a small flat disc from terracotta clay (like a
biscuit or a cookie). We used plastic dinosaurs as well as plastic
trees to make imprints in clay. After firing I had each child add a
small amount of white paint using a sponge roller, just to bring out the
texture details a little more.
The kids enjoyed pretending these were biscuits or cookies.