After we created a little with clay - and unintentionally experimented with how fragile or not the air-dried pieces could be when Kay accidentally broke some - I somehow came to the thought: dinosaur eggs. These would make for great dinosaur eggs. (Don't ask how my mind works - it would frighten you...)
Making sure Kay was not around, I found a few of her small toy dinosaurs and formed the clay around them so they were hidden in something like an egg-shape. I left them to sit for 2 days, to be sure they were good and hard. Still, I worried they would be too easy to crack. I needn't have worried.
Then came the fun part - excavation time! I made a big show of laying the eggs down. I had suggested Kay bring out her tool kit because "she might need it". She went straight for the hammer (do I know this kid, or what?) but I reminded that their might be babies in the pretend eggs. Really, I didn't want one whack of the hammer to end the whole activity.
So she searched through her tool bag - screw driver, pliers, nope nothing was working. So she went to town with her hammer.
Clearly these little eggs were hard to crack - just as I hoped they'd be. I offered no suggestions, but watched with a proud mama's eyes as she tried to figure out how to get those tricky eggs open.
Finally, she found the secret - cracking them on the side of the water table as if she was baking. That cracked the egg in half and used her tools to "free" the baby dinosaurs from the egg. (No dinosaurs were harmed in the making of this activity.)
Then, another random thought - would the shards of clay leave any mark on the cement? Yes - yes they did! I was as excited as if I'd discovered fire. This clay-as-chalk may be common knowledge to others, but, hey, let me have my moment!