Revisiting the sedimentary record of the rise of diatoms
Sophie Westacott, Noah J. Planavsky, Mingyu Zhao, Pincelli M. Hull
Abstract
Significance The fossil record has been used to suggest that diatoms rose to become one of the most dominant primary producers in the world over the past 20 million years, thereby transforming the global silicon cycle. Here we provide new evidence that the fossil record of diatoms is strongly influenced by changes in preservation potential. We show that changes in deep-sea sedimentation rate and temperature over the Cenozoic Era (the past 66 million years) would have led to better diatom fossil preservation toward the present, producing an apparent rise that does not necessarily reflect a primary ecological signal. This finding is transformative for our understanding of the Cenozoic silica cycle and diatoms’ role in it.