Paleocene-Eocene Thermal Maximum (PETM)

This project investigates the response of organisms to the Paleocene-Eocene Thermal Maximum (PETM), the most rapid and significant climatic warming pulse of the past 65 million years.

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?

Coastal ecosystems around the world are increasingly fragile and ecologically degraded, but many communities rely on them 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.

Rationale

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.