Bivalve shell Trace Fossil Burrow

Cretaceous shipworm – with no ships to bore into!

Here is a really unusual fossil – the boring made by a bivalve shell. Modern shipworms are also bivalves, not worms. Today they bore into wooden piers, docks and ships. We don’t know what the Cretaceous shipworms bored into, but it is most likely that it was a piece of driftwood. Wood is not preserved in chalk and the only reason this is fossilised is because the boring has been replaced with flint.