Paleocene-Eocene Thermal Maximum

The Paleocene-Eocene Thermal Maximum (PETM) was the most rapid and significant climatic warming pulse of the past 65 million years. This project investigates the response of organisms to the PETM, informing our understanding of current global warming in similar habitats.

The PETM occurred around 55.8 million years ago. Global temperatures rose by 6°C, leading to an increase in atmospheric CO2 levels comparable to the rate of current anthropogenic warming.

Some organisms were unable to adapt to rapidly changing environmental conditions and became extinct. These included:

  • bottom-dwelling deep-sea organisms
  • open-ocean plankton
  • terrestrial mammals

Little is known about the response of shallow-water marine organisms to the PETM and how coastal ecosystems themselves may have changed. 

Research aims

We are studying molluscs and cartilaginous fish (sharks and rays) from extensive fossil deposits in north west Europe to answer these questions:

  • Did patterns of extinction and evolution change?
  • Did overall levels of biodiversity change, and if so, over what interval of time?
  • What was the effect of the PETM on the ecology and structure of shallow marine communities?

Protecting future ecosystems

Coastal ecosystems around the world are increasingly fragile and ecologically degraded. Many communities depend upon these environments for a wide range of ecosystem services. 

We hope that documenting the response of organisms to the PETM will help us to predict the result of current global warming in these habitats.

Project lead
Jon Todd portrait
Dr Jon Todd

Invertebrate palaeontologist specialising in Mollusca, Earth Sciences department.

Ken Johnston
Dr Kenneth Johnson

Invertebrate palaeobiologist in the Earth Sciences department.