Snail shell

Portland Screw

This Portland roach stone contains high-spired snails, Aptyxiella portlandica, also called Portland screws. There are also bivalve shells, visible at the top and right side of image. They are all preserved as internal casts – the shell itself has been dissolved away to reveal the hollow space inside that filled with sediment.

Find out more on the molluscs page.

Common name

Snail shell

Scientific name

Aptyxiella portlandica

Type

Molluscs > Gastropods


Strata

Portland Limestone

Time period

Upper Jurassic

Age

150 million years

Where found

Unknown

Found by

Unknown

Museum

Portland Museum

Accession number

POLPM.1993.262