Optional Activities
- Build a Coral Reef Diorama: Use a shoebox and modeling clay or paper to build an Ordovician reef scene. Include corals (finger shapes), crinoids (stalked sea lilies), trilobites, nautiloids (coiled shells), and brachiopods (clamlike shells). Label each organism and note that none of them have close living relatives, this world is utterly alien.
- Shell Collection Compare: If you can gather any shells (beach, craft store, or online), examine them for symmetry. Brachiopods have top-bottom symmetry; bivalves (clams/mussels) have left-right symmetry. This tiny difference reflects different evolutionary origins, and brachiopods were FAR more common in the Silurian than clams are today.
- Is Coral a Plant or Animal?: Determining whether coral is a plant or an animal is a classic biological puzzle because it functions as a complex, living partnership. While corals are officially classified as animals, specifically marine invertebrates related to jellyfish and anemones, they host microscopic algae called zooxanthellae within their tissues. This is a fun research project for all ages.
Digging Deeper Activities
- Great Ordovician Biodiversification Event (GOBE): The Cambrian gave us body plans, but the Ordovician multiplied diversity explosively, tripling the number of marine animal families. Research the GOBE and compare it to the Cambrian Explosion. What caused it? What ended it (the Ordovician mass extinction)?
- Silurian First Land Plants: The Silurian saw the first vascular land plants (like Cooksonia, tiny, leafless, just a few centimeters tall). Research why the move to land was so challenging for plants and what adaptations made it possible. Then compare to the animal transition to land that followed in the Devonian, which came first, plants or animals, and why does the order matter?