As I've mentioned before, S loves dinosaurs.  Recently she'd become curious about dinosaur fossils and was wondering if we could make some of our own.  So we decided to try it out!  It's actually quite easy and very fun.  We've revisited this activity several times since and it's definitely a favorite around here.  I was happy to find these amazing dinosaur bones on Amazon.  There are 12 to a set, and they even have labels with the names of the dinosaurs on them!

Materials wise, you need an oil-based clay.  We used Crayola Model Magic.  It worked really well, but I'd chosen blue and it did leave a blue residue.  So I'd recommend using the white Crayola Model Magic if you go that route.  After I first wrote this post we experimented a bit more with it when we made our Plaster Handprint Spiders at Halloween.  And we discovered that our go-to cook playdough recipe is oily enough that you can use it in place of model magic if you'd prefer.  I have heard that storebought playdough is not oily enough and it will stick to the plaster.

 I bought the "Strong Cast Plaster" shown below for $4 from Michaels, but you can use regular Plaster of Paris from Home Depot instead.

For the first step, you want to get some sort of container with edges so you don't spill the plaster.  We used an old Gladware container whose lid has long since disappeared.  Make a nice layer of clay - if you get it nice and thick, you can press your fossil in harder and it will come out looking cooler.

We pressed ours in as far as we could to get the maximum amount of detail.

 S got to follow the directions and measure out the plaster mix into our mixing container. This was the first model we made, so we were sure to use lots of plaster mix.  Since then we've made several that are thinner and they're pretty sturdy as well so long as you wait until they are completely dry. 

S also was in charge of mixing.  I tried to take a back seat as much as possible.  Her coordination has really taken off in the last few months, and she's able to do these things without (or with minimum) spilling.

Carefully pouring the mixture over the mold.  The slower you go, the less likely air bubbles are.

It takes about an hour for the plaster to fully set (it may take longer if you've added a thicker layer of plaster).  We put a timer on and played so that she didn't go crazy waiting!

The finished mold.  Note the blue hue from the use of blue Model Magic.

After she was done painting it.  I'm pretty sure this is what actual dinosaur fossils look like.  Or maybe it's just what they should look like?  Everything *is* better with glitter, after all.

For even more dinosaur fun, be sure to check out our No Sew Dinosaur World Playmat and our Dinosaurs and Sticky Mud Small World!

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All activities here are activities I feel are safe for my own children.  As your child's parents/guardians, you will need to decide what you feel is safe for your family.  I always encourage contacting your child's pediatrician for guidance if you are not sure about the safety/age appropriateness of an activity. All activities on this blog are intended to be performed with adult supervision.  Appropriate and reasonable caution should be used when activities call for the use of materials that could potentially be harmful, such as scissors, or items that could present a choking risk (small items), or a drowning risk (water activities), and with introducing a new food/ingredient to a child (allergies).  Observe caution and safety at all times.  The author and blog disclaim liability for any damage, mishap, or injury that may occur from engaging in any of these activities on this blog.