Plankton evolution and the Paleogene/Neogene transition

Project Description:

The modern oceanic phytoplankton comprises three algal groups – the diatoms, coccolithophores and dinoflagellates – with diatoms currently dominating both biodiversity and productivity.

Fossil biodiversity estimates suggest that this dominance may be a relatively recent phenomenon and that the late Eocene to early Miocene time interval (~34-20 million years ago) saw significant decline in the diversity of calcifying phytoplankton (coccolithophores), coincident with a rise in the siliceous diatoms.This time period also saw major climatic re-organization with high latitude cooling, ice sheet growth on Antarctica and glacial/interglacial cycles.

The project will document the structure and timing of coccolithophore diversity through this interval and test whether climatic shifts played a significant role in plankton evolution, population variability and population composition. The research will focus on new, well-preserved sample material recovered during IODP Expedition 342 in 2012.