Pteropods are holoplanktonic molluscs presently endangered because their fragile aragonitic shell is very sensitive to ocean acidification. The preservation of pteropods, and in particular of the mesopelagic Heliconoides (Limacina) inflatus, has been used to assess aragonite saturation state in Quaternary sediments (Limacina Dissolution Index, LDX) as an inferred proxy for climatic changes. Three ...