An Experiment to Demonstrate how Gastroliths Help a Dinosaur Digest its Food

Last week in our dinosaur unit we learnt that Stegosaurus, our dinosaur of the week, was a herbivore and ingested stones known as gastroliths (a bit like hens ingesting gravel), which helped to break down the tough plant material.  This was a glaring opportunity to experiment and investigate a bit further.


Equipment for each child


  • two Ziploc bags, one labeled with stones and one labeled without stones
  • Seven good sized stones from the garden
  • Lots of vegetation from the garden
  • Timer
  • Water (2 cups)




  • Place an equal amount of vegetation in each of the two bags.
  • Add a cup of water to one of them, zip it up.
  • Set the timer at 3 minutes.
  • Have the child agitate the bag as much as they can during that three minutes.


  • Add a cup of water to the second bag and place the seven stones inside and do the same, agitating it for three minutes










For lots more inspiration feel free to visit my dinosaur pinterest board:


  1. I love your experiment, it´s great! Thanks a lot for sharing and working so much on your blog, it´s really special!
    Once we learned about Dinos, we made hats. We used (big enough) balloons with air inside, thin paper and dark green goo to form the helmets. For horns and plates we used toiletrolls and cardboard. When dry, we cut out the hat form and painted eyes and patterns using acrylic paint. It was very funny for the children, they wore their helmets (we added rubberbands for a better fit) for years!

  2. That is a really cool experiment! I had already decided that dinosaurs was going to be my next little kid unit study, so I’m saving this post in case we want to try it later 🙂 I’ve decided this year that one of the best things about having a second “group” of students is that I can revisit my favorite studies from Firecracker and Rose’s first couple of years with Monkey and Owlet now.

    1. I’m really enjoying teaching the littles at the moment. They are more science, maths and art orientated than science so I am hoping to learn lots about those subjects this time round!

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