After preparing the sediment samples so that the microfossils can be examined, the biostratigraphers examine to species to find important biostratigraphic markers that can tell us the age of the sediments. The radiolarians and the diatoms have been especially helpful for determining how old the sediments are. In this picture, the diatom and radiolarian workers on the night shift are comparing their data and working out any disagreements between the groups.