This research used samples provided by the Ocean Drilling Program (ODP). ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. Funding for this research was provided by the Foundation for Research, Science, and Technology, Wellington, New Zealand, as part of a New Zealand Science and Technology Postdoctoral Fellowship. I thank Alan Cooper, Co-Chief Scientist for Leg 188, Stanford University, for allowing this work to be undertaken, Peter Barrett for the initial idea, and John Carter, Victoria University of Wellington, for ongoing discussions about phytoliths. I also thank the reviewers of this manuscript for their helpful comments.