The sea water contained large quantities of calcium carbonate ... Many of the rock layers contain fossils of these organisms. Fossils formed when an animal's shell or other hard structure is buried ...

When they died, the plants and animals were buried by mud, sand, or silt on the sea floor ... were preserved. Fossils can be formed in several ways. Buried bone and shell contain tiny air spaces ...

Our special video series looks at some of the more unique shells at the Bailey-Matthews National Shell Museum on Sanibel, ...

Leal at the Bailey-Matthews National Shell Museum & Aquarium on ... world-record-sized shells, deep-sea species, land snails, and ancient fossils.

Their shell is usually a flat spiral shape ... If you look in chalk rock you might find lumps of flint that have sea urchin fossils in them. And when you are on a beach keep a look out for a rounded ...

This is because they lived in the sea, where sand or mud could bury ... as an internal and an external mould. The shell itself has dissolved away. Uplift, weathering and erosion: why we can find ...