Jocelyn Sessa, PhD, is a paleobiologist who uses the fossil record as a natural laboratory to study times of change in earth’s history. Her research melds fossil and modern data to elucidate the response of mollusk faunas (clams and snails) to environmental perturbations across space and time. Sessa’s studies span a wide range of events, from the mass extinction that killed off the dinosaurs to past climatic fluctuations, including intervals of past and present global warming. By analyzing the chemistry of mollusk shells, she also reconstructs the climatic conditions that affected ecosystems.
A new research initiative is focused on determining historical baselines for modern ocean acidification, to ascertain whether certain regions or species in the global ocean may be more resilient to future changes in ocean chemistry than others. Sessa’s hunt for mollusks is a worldwide endeavor, with fieldwork along the US eastern seaboard, the US Gulf Coast, California, Romania and Angola. An important facet of her scholarship is mentoring high school through graduate students in research projects. Sessa is passionate about making science accessible to everyone. Since 2007, she has participated in programs to engage groups under-represented in the sciences, and is excited to continue this work in the Philadelphia Area.