Photosynthesis in the world's oceans by marine algae is responsible for approximately 50% of CO2 fixed into organic carbon. Aquatic primary producers are intricately linked to the climate system due to their reliance on CO2 as a substrate for photosynthesis and role in the removal and export of carbon from the surface ocean to marine sediments. The evolutionary history of marine algae was shaped by changes in the climate system. As a result, fossilized marine algae and modern re...