As the names suggest, the subdivision of annelids into the Errantia and Sedentaria matches their overall lifestyles (Fig. 1). Members of the Errantia are free to move about, and crawl, swim or burrow.

Clusters of fossil serpulid worm tubes, like these Rotularia from the British Eocene, are common fossils in many Mesozoic and Cenozoic marine rocks The Museum’s collection of fossil annelids is both ...