Measurements of the CaCO3 content and the CaCO3 size index on a core from the equatorial Atlantic's Ceara Rise reveal a pronounced dissolution event associated with the transition between MIS 5e and 5d. We tentatively correlate this event with the dramatic drop in atmospheric CO2 content that occurred at the end of MIS 5e. Attempts to quantify the carbonate ion concentration drop associated with this event failed because the shells in this zone had been largely destroyed by dissolution. By leaving out the sonification step in our cleaning procedure, we were able to rescue enough shells to weigh, but they showed no dramatic weight loss. We attribute this to the survival of the hardiest shells.