from en wikipedia. A large ammonite, 0.6 metre (2 feet) across, outside the Portland Museum, Portland, Dorset, England.
Picture taken by Adrian Pingstone in 1987 and released to the public domain.

This work has been released into the public domain by its author, Arpingstone . This applies worldwide. In some countries this may not be legally possible; if so: Arpingstone grants anyone the right to use this work for any purpose , without any conditions, unless such conditions are required by law.