Cheilostome bryozoans use 2 calcium carbonate biominerals to form their skeletons:
Calcite is the primitive biomineral for cheilostomes but since the Late Cretaceous several clades have switched to partly or completely aragonitic skeletons.
We are investigating the timing of these switches and their relationship to changing seawater chemistry.
The biomineral used also has relevance in the context of contemporary ocean acidification as aragonite is substantially more soluble than calcite.
In collaboration with a group from ENEA, La Spezia, Italy, we are studying the effects of acidification on bryozoan colonies deployed at a site near Naples where venting of volcanic carbon dioxide increases acidity on the seabed.