Do you know a dinosaur fan? Are YOU a dinosaur fan? If so, here’s a science-y way to do a dino dig, right in your backyard (or kitchen)!

You will need

  • Mixing bowl
  • Measuring cups
  • Water
  • Light plaster
  • Sand
  • Cornflour
  • Aluminium container (rectangular BBQ trays work well)
  • Red food dye
  • 2-6 small dinosaur toys
  • Old toothbrush
  • Face mask


If you go outside, be sun-safe and let an adult know where you are. Be careful with the tools you use to excavate, handle them with care and excavate a safe distance from other excavators.

outdoor hazard icon
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What to do: make the excavation kit

  1. Pour 1/4 cup of water into a clean mixing bowl.

  2. Put on your face mask and measure 6 tablespoons of light plaster powder. Gently sprinkle each tablespoon over the water in the mixing bowl.

  3. Let the plaster sit in the water for 1 minute.

  4. Mix the plaster into the water using a spoon.

  5. Add 1 and ½ cups of sand into the plaster mixture and mix it well. You can take off your face mask now.

  6. Place 1-3 dinosaurs in the aluminium container.

  7. Pour the sand-plaster mixture into your container until it completely covers the dinosaurs.

  8. Set your container aside to dry for at least 60 minutes. While you wait, rinse your mixing bowl, spoon and measuring cups.

  9. Put 1 cup of water in the clean mixing bowl.

  10. Put 2 cups of cornflour into the mixing bowl and use your hands to mix it in, getting rid of any clumps.

  11. Add 5 drops of red food colouring to your cornflour mixture and mix it all together with a spoon.

  12. Place 1-3 dinosaurs on top of the hardened sand-plaster in your container.

  13. Pour the red cornflower mixture on top of the hardened plaster until it covers the dinosaurs.

  14. Set your container aside to dry overnight or until the top layer is hard and dry.

  15. Note: excavate within 2 days of making the kit as the cornflour will mould. Avoid doing two layers of cornflour as it will mould before the whole kit dries.

What to do: excavate dinosaurs!

  1. Take your excavation tool (old toothbrush) and the excavation kit outside, ideally somewhere close to a hose so the area can be washed afterwards as cornflour can be messy! If you’d prefer to stay indoors, set down newspaper over your working area.

  2. Put on your mask.

  3. Use your tools to remove the chalk “rock” in small chunks and dig your dinosaurs out! Use the handle side of the toothbrush to knock bigger pieces away.

  4. Use the top of the toothbrush to dig away the layers of “rock”.

  5. Use the bristle side of the toothbrush to gently remove cornflower or sand from around your dinosaurs.

  6. Take note of the dinosaurs you find, what order you find them in, and the colour of the layer they come from.

  7. Wash away any remaining sand or cornflour from your toys. Congrats! You’ve completed your dinosaur dig.

What’s happening

Just like a geologist or a palaeontologist, you used tools to find evidence of ancient living things in the “rock”.

We know about ancient life from fossils, which are usually found in sedimentary rocks. Sedimentary rocks get their name from sediments, which are very small bits of existing rocks that get worn away by wind or water. These tiny sediments build up and create layers of sand or mud. Eventually, the weight of the sediments on top turns the bottom layers to stone and any buried living things become fossils.

The layers of sedimentary rock can tell us a lot about the passage of time. Each layer gets set down in a predictable way, with older layers on the bottom and younger layers on top. Knowing this, the location of a fossil within the rock can tell us when it died and got buried in sediment. In this activity, the dinosaurs in the sandy bottom layer would be older than the dinosaurs found in the top red layer*.

Stratigraphy is the field of geology where scientists piece together Earth’s past using rock layers. No one rock tells the whole story, so it takes some detective work and collaboration among geologists. Looking at rock layers all over the globe is allowing geologists to recreate Earth’s 4.6-billion-year story!

*Author’s Note: If you would like to increase the accuracy of your two-layer dinosaur excavation kit, Wikipedia is usually a reliable source for looking up when specific dinosaurs lived.

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