Calcium isotope ratios of malformed foraminifera reveal biocalcification stress preceded Oceanic Anoxic Event 2

These data include bulk carbonate calcium, oxygen and carbon isotope data from Gubbio, Italy and the Angus Aristocrat Core from the Western Interior Seaway in Colorado, USA as well as foraminiferal calcium, oxygen and carbon isotope data from Gubbio, Italy. All calcium isotope data were generated using a high-precision Thermal Ionization Mass Spectrometer method. Carbon and oxygen isotope data were generated using an Isotope Ratio Mass Spectrometer.