Ammonite

Here is a bed of the ammonite Arnioceras preserved in calcite crystal and iron pyrite. The centres of the ammonites are preserved in calcite but the body chambers (the part of the shell the animal lived in) have been filled in with the pyrite. The local collectors call this ‘Gold Stone’ for obvious reasons.

Arnioceras is one of the most common ammonites in the Lower Lias of Dorset.

Find out more about ammonites on the molluscs pages.

Common name

Ammonite

Scientific name

Arnioceras

Type

Molluscs > Cephalopods


Strata

Lower Lias

Time period

Lower Jurassic

Age

190 million years

Where found

Black Ven, Lyme Regis

Found by

Pete Langham

Museum

Lyme Regis Museum

Accession number

L.1986.280.12