ECOLOGICAL SELECTIVITY OF CORALS DURING THE PALEOCENE AND EOCENE

Scleractinian corals are incredibly sensitive to changes in their environment. Significant and rapid stresses, such as increased temperature, hypercapnia, and ocean acidification, can lead to a decrease in coral cover and even coral extinctions. During the Paleocene-Eocene Thermal Maximum (PETM, 55 Ma), a major carbon-cycle perturbation event occurred, which is associated with extreme changes in climate and marine environmental conditions. Despite the lack of coral reefs during the PETM, there is no significant drop in coral biodiversity; in fact, corals diversify during this interval. The PETM is one of the best analogues for modern climate change, so by studying patterns of extinction and survival during this event, we can better predict how modern reef ecosystems will be changed due to modern and future marine stresses.

This study aims to identify whether ecologic selection (based on physiology, behavior, habitat, etc) plays a role in the survival and extinction of Paleocene and Eocene coral taxa. Because many Paleogene coral genera are extant, paleobiologists can make reasonable assumptions about their ecology 55 million years ago. A global database of all corals from the Paleocene and Eocene and their traits were compiled, extinction rates were calculated, and statistical analyses were used to identify common traits among corals that survived the PETM or went extinct. These results allow us to understand how coral genera will react to changing climate and test the hypothesis that certain traits (e.g., flexibility in diet, polyp connectivity, etc.) allow corals to survive periods of prolonged environmental stress.