Dear Rosie M. Sheward and co-authors,

First I would like to thank the two reviewers for their extensive review of your manuscript and of course you for your thorough reply. Based on your reply I have the impression you have already updated your manuscript according to the two reviews, but I do have a few remarks of my own.
I completely agree with you that looking at a sample through a light microscope would or could be the first indicator of growth, how healthy/happy were the cells? This could hold for cultures as well as paleo-samples and in order to assess the information from paleo samples you need to generate a framework based on culture studies and environmental samples. The one thing not mentioned I this manuscript are potential preservation biases, I not sure if anything is known about coccosphere preservation biases or if this would be part of ongoing research? I can imagine that, as referee #1 mentions, the size ranges are similar for different growth “phases” and only the averages different, that a size preservation bias could really upset the paleo-results. I am aware that this is not necessarily part of the presented work, but since you put the manuscript in a paleo reconstruction framework I think a few sentences on possible preservation biases might be warranted.
If you and your co-authors will address the reviewers comments as discussed in your reply and the raw data will be available as supplemental table I think your manuscript will make a nice contribution to Biogeosciences. I am looking forward to the final version of your manuscript.

Best regards,

Marcel

Dear Rosie M. Sheward,

Thank you for addressing the reviewers comments and submitting the revised version of your manuscript. I had on minor last comment, I am not sure what your error margins are, but in line 480 I think 10.9 pmol C cell-1 is probably accurate enough.

Best regards,

Marcel