Tim Bralower and Maria Rose Petrizzo are thanked for making biostratigraphic data available prior to publication. Robert Henderson is thanked for assistance at the drafting stage. Tim Bralower, David Rae, and Mitch Lyle are thanked for their helpful reviews and comments that improved the paper. This research used samples and/or data provided by the Ocean Drilling Program (ODP). ODP is sponsored by the U.S. National Science Foundation (NSF) under management of Joint Oceanographic Institutions (JOI), Inc. Funding for this research was provided by Australian ODP.