Data collected in this study from IODP Site U1486.

Samples are ordered by depth within each segment of the inter-hole splice. Depths below sea floor on the CSF-A scale are converted to composite depths on the CCSF scale according to offsets given in the affine table in Ref [52]. Ages are calculated within the age-model tie points indicated and as given in S1 Table. Sample weights and Pulleniatina coiling counts of 50 specimens are reported. In the intensive study windows indicated, samples were split and the absolute number of sinistral and dextral specimens recorded; these data were substituted for earlier counts, and those counts discounted, in these windows only. (XLSX)