Have you ever seen or touched a starfish? What about a sea urchin or a sand dollar? These 3 organisms have something in common – they are all grouped as echinoderms. Echinoderm? What does that mean? "Echino" means spiny and "derm" means skin. You may have heard of your epidermis. That's your outside skin. Echinoderms all have some type of spiny structure on the outside.
All echinoderms have spiny or bumpy skin. Their bumps aren't always easy to see like the bumps on a toad's skin, but they are there if you look closely.
All echinoderms are also invertebrates. This means they do not have a back bone. You have a back bone that helps hold your body up straight. Echinoderms crawl on the ocean floor. They do not need to be able to stand up straight like we do.
Learn more about Echinoderms and then make one in today’s Let’s Make It!
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