Ever since I’ve figured out what they were, local Pinna fossil specimens are a personal favorite to find. In examining the remaining shell material in these fossils, I have been able to see the prismatic layer represented on the shell hinge in at least two specimens. The specimens below show the detail.
The layer in a specimen from May 30th, 2019
The layer from Sea Pen III
- The Prismatic Layer of Pinna: A Showcase of Methodological Problems and Preconceived Hypotheses – By Yannicke Dauphin, Alain Brunelle, Kadda Medjoubi, Andrea Somogyi and Jean-Pierre Cuif – Minerals – Volume 8, Issue 9