Larger Pacific Striped Octopus
- Dec 24, 2002
Most molluscs have two calcareous shell layers, the outer prismatic layer and inner nacreous layer. What I was wondering is if there are any theories as to why this might be? I have a Cretaceous ammonite fossil that still has some of the nacreous layer intact, and I was wondering if there might be any evolutionary advantage to having calcium crystals in the shell in two distinct layers (one that gives us that oh-so-pretty Mother of Pearl of which we are so fond).