Crystal growth kinetics as an architectural constraint on the evolution of molluscan shells

Significance Using notions from classic materials science, we expand our understanding of the macroscopic morphospace of possible molluscan shell shapes to the level of possible ultrastructures that comprise them. This provides us with a unique opportunity to explore this morphospace using well-developed analytical, theoretical, and numerical tools and to test the effects of a discrete number of parameters on shell biomineralization. The physical model presented here sheds a new light on the evolutionary aspect of molluscan shell ultrastructural fabrication and suggests that the repeated “discovery” of some mineral morphologies partially reflects a series of architectural constraints provided by biomineral growth kinetics.