By Dr Jonathan Lewis and Prof Melanie Leng The shells of molluscs from all over the world – on land, in lakes, and in the ocean – contain very detailed imprints of past climate change. Using isotope analysis, we can extract these signals and start to piece together long-term climate variations. You will never look at a garden snail in the same way again! What are molluscs? Molluscs are soft-bodied (invertebrate) organisms that are widespread in terrestrial, freshwater, and marine habitats. We can split them into two basic groups: Gastropods: Molluscs with up to one shell or ‘valve’ (such as snails or slugs) Bivalves: Molluscs...