You have answered the comments of the reviewers well, but I feel Reviewer 2 brings up a valid point. You cannot draw these conclusions based on one specimen. There are several published papers showing large differences in mollusk skeleton elemental ratios between specimens and species. Vital effects can result in large differences in relationships between elements and precipitation rates and even between different elements even within the same species. For example, look at the differences in Mg/Ca ratios between scallop specimens in Lorrain et al. 2005 cited in your manuscript. Also, consider the large differences in Sr vs precipitation rate between species shown in my own paper, Gillikin et al. 2005 ( doi:10.1029/2004GC000874).

I urge you to include more data from a second specimen at a minimum. You need to replicate these patterns to draw the conclusions you discuss. With additional data your manuscript will be more well accepted by the community.

Thank you for your revisions. I have gone through them and feel you have adequately addressed all reviewer comments. I have only very minor comments I would like you to consider before publication:

Abstract - mention new specimen.

P2 L4 add: from inorganic calcite experiments.

P3 L 8 please add a sentence about drill bit diameter, drill depth and distance between holes. If it is the same as for the new specimen, then move that info up in the paragraph.

Supplement: Add new data from second specimen.