Though, the diatom species have a long stratigraphic record from upper Cretaceous to Holocene, many short ranging species with few million years or less serve as a well-developed biohorizon with ages calibrated to the radiometrically dated geomagnetic timescale. The combination of multiple tools including diatoms results in age control of million years to as little as hundred-thousand-year resolution. Although rapid mass extinction of marine diatoms during that time is rare, multiple sharp evolutionary turnovers during Cenozoic were identified (Figure 4) and are correlated with global benthic foraminiferal oxygen isotope curve (Scherer et al., 2007). The rapid evolution of marine diatoms during Cenozoic time coincided with major climatic cooling period at high latitude or major reorganization of ocean’s surface water circulation (Scherer et al.,
Though, the diatom species have a long stratigraphic record from upper Cretaceous to Holocene, many short ranging species with few million years or less serve as a well-developed biohorizon with ages calibrated to the radiometrically dated geomagnetic timescale. The combination of multiple tools including diatoms results in age control of million years to as little as hundred-thousand-year resolution. Although rapid mass extinction of marine diatoms during that time is rare, multiple sharp evolutionary turnovers during Cenozoic were identified (Figure 4) and are correlated with global benthic foraminiferal oxygen isotope curve (Scherer et al., 2007). The rapid evolution of marine diatoms during Cenozoic time coincided with major climatic cooling period at high latitude or major reorganization of ocean’s surface water circulation (Scherer et al.,