Make your own Fossils

A few years ago I dreamed up this project for my youngest son's Dinosaur themed party. At that time they didn't sell kits for these. I hadn't seen this idea any where. I just thought of how you can use plaster to pull up impressions of foot prints in sand or dirt or whatever. On the East Coast there are real Dinosaur foot prints in rock that you can make your own plaster cast of. I remember a sign with instructions on how to make the cast. This picture is from my oldest son's World Explorer party this year. It was a huge hit for all the kids. Their ages ranged from 4 years old to about 11 years old. When we did this the first time the ages were even younger still. I would say that any child that either likes to play with Play Doh, likes Dinosaurs or fossils would love this project. I think that even some adults would love this project.

What you need to get:

Oil based clay the kind you have to bake...We used Sculpty clay

(if you use something like Play Doh that is water based it will get soggy and make it difficult to remove from your plaster fossil. Though it will be more like an added excavation project, using tooth picks to scrape Play Doh out of the details, but it will take hours, we tried it. Be careful while the plaster is still soft. I would say for little kids you are better off with oil based clay.)

Plastic Dinosaurs-skeletons look the coolest but you can any small plastic Dinosaurs

Leaves with interesting texture (optional)

A shallow container just bigger than your Dinosaur (we used plastic food containers you can buy at the store)

Aluminum foil

Plaster of Paris

Something to mix the plaster in (that you will throw away when done)

Something to measure water and plaster powder
Something to stir the water and powder together (you will throw this away when done)

We set up a large table with a throw away table cloth and had the kids do this outside. Clean up was as easy as rolling up the table cloth and throwing it away. However, the table cloth was a mess with plaster powder and bits every where. Do this outside, you will thank me.

First you will need to give each child a sizable chunk of clay (don't worry you can reuse the clay for something else since it won't dry out). They will have to kneed it to soften it up. (his is great for kids with sensory issues and gives great input to their hands. Also great for strengthening hand muscles to get them ready for writing and other fine motor skills. Also a great way for adults to release some tension that comes with planning a party.) If you are doing this for a party, you can have the kids do this in shifts. It will take about 20-30 minutes for these to dry. So plan on doing these right away. These were the party favors for the kids to take home along with some other trinkets from the pinata. Oh and when you are done put the Dinosaurs in your sand box and have them do a Dinosaur Dig!


Then they will need a piece of foil large enough to line their shallow container. Crumple the foil some first before lining your tray/container (it will give an interesting rock like texture around your fossil) Be careful not to rip it. You don't want the plaster to leak out any holes.

Make your lump of clay wide and long enough for your dinosaur to fit. Don't think it out too much, you don't want to hit the bottom of the clay while pressing in your dinosaur. You will want to press the clay into the foil to try to prevent the plaster from seeping under the clay. It will make removing the clay easier later on. Lay out your dinosaurs. Let the kids decide what they want to do. Some of the kids at the party took sticks and pressed them in. Some drew their initials into it. Here you can see I used several types of dinosaurs. Some of the kids did all of the little dinosaurs, "like a mass grave." Others added a little dinosaur next to the large one and said "it's Mama and Baby." Kind of depressing if you ask me but they were having tons of fun letting their stories come to life. In the picture above I picked some of my parsley because I thought it would leave an interesting pattern. Look around and see if you have something that you can imagine is prehistoric looking.

When making your impressions, you are going to have to help your child make sure the whole side of the dinosaur is pressed firmly into the clay. You may have to rock the dinosaur as you press to get the entire profile. The neck, tail and spine at the pelvic area are usually the places that don't just press in. We had to show the kids how to press on the legs and then all along the dinosaur to make sure we got a good impression. If you are careful you can put the dinosaur back in place if you need to go back over an area. Some kids will find that they have rocked their Dinosaur two much and made a double image. The beauty of this project is they can mash it up and start over till they have something they like. This picture is a bit deceiving because it almost looks like a positive image, when it is in fact a negative image. When you pour the plaster over you will get the positive image and it will look like a skeleton that has been partially excavated.

Mixing and pouring of the plaster should be done by an adult. Follow the directions on the package for how much water and how much plaster you need. Remember if it is really dry and hot the day you do this, you should add a bit more water. It will give you more time to work with it before it begins to harden. Plaster starts setting fairly quickly so mix up only enough for the fossils that are ready. Pour a fairly thick layer of plaster over the clay. You want it to be thick enough that it won't break easily. Remember the edges will be thicker than the center where the clay is. It is a good idea to either make your plaster a touch on the runny side and be sure to tap your tray on the table or ground to encourage all the plaster to fill all the little spaces of the skeleton. Tapping will make the air bubbles come up to the surface. Adults should do this for little kids. You don't want plaster flying around. Did I mention that plaster can be messy? This is the fun part. This is where all the OOOOO and AAAAAAAAAAs come in. Seriously this is where all the other parents think you are the COOLEST MOM EVER!!! Your party will be talked about for a really long time, probably years and years. Once the plaster is dry use the foil to help you lift the fossil out of the container. Gently pull the foil away. It is ok to rip it but if you are careful you can place your fossil on top while you pull away the clay and it will catch some of the flaking plaster. The thin edges make break off a bit and this is where some more mess will happen, particularly if some of the plaster leaked under the clay.

Now the kids have a fossil that they can proudly display in their room on a plate stand or on a wall hanger of some sort. We didn't have the kids paint them up at the party. This project takes up a bit of time as it is. I think they look great just the way they are. Mine will remain unpainted. All of the kids were excited about the fossils they made. This is crafting made cool! Boy and girls alike will love this. I know from personal experience.

My brother was here for my son's Birthday party a few months ago. He did a fantastic job running the fossil making table for me while I was able to focus on making sure other things were ready to go. I will also say that he had as much fun as the kids doing this. He does not often have opportunities like this to make something with kids. Grandparents are also usually happy to help out with projects like this. My Dad also got into this project and helped out. I also noted that many of the parents were standing by to see this project in action.

I always recommend getting other adults involved in manning an activity like this. Give them a quick tutorial on what the project is and have one or more adults work with the kids. You will thank me for delegating some of the party activities. At this party I asked a friend to take pictures. It ensured that I got more than just a handful of party pictures. Isn't that what family and friends are for? They make my life so much easier during parties. Too many years I did all the work and didn't have any time to socialize because of it. Because I delegated this on the last party I was able to socialize far more than any other party we ever had. I never knew parties could be so stress free!!

Katrina