Nature & Environment
Life in the Palaeozoic
...classes may seem unrelated, they represent evolutionary variations on the same theme - the molluscan bodyplan. Three classes, each of which range from Cambrian to Recent, are particularly important, both as fossils and today: the Bivalvia - bivalves (e.g. cockles, mussels and oysters) (Figure 1e); the Gastropoda - gastropods (e.g. slugs and snails); and the nektonic...