Weighs 189 grams
Measures 80mm x 70mm x 10mm approx
Some ammonite's bear intricate patterned details on their outer surface called Sutures. These are located beneath the external shell wall, and are often visible if it has been subject to weathering or artificial polishing. These patterns mark where the walls of the chambers, Septum, meet the outer wall of the ammonite shell. The bulk of the septum is relatively flat, but becomes folded where it meets the outer shell. This method of construction is thought to have provided strength to the shell when diving to deeper depths. Suture patterns are very useful for distinguishing different species of ammonite.
A polished fossil ammonite from Madagascar with traces of opalescent shell still remaining.
The suture lines are clearly visible, very complex and form convoluted and subtle patterns of varying shades of brown and cream.