The shark fossil record spans 400+ million years and includes past ‘experiments’ in climate change. Much of this record is composed of shark teeth, which have a chemical composition that prevents alteration or degradation during fossilization. Fossil shark teeth are often analyzed for their stable isotope composition to reconstruct environmental conditions, but linkages to ecology with trophic level or habitat use have remained elusive. My research group explores techniques and approaches in modern sharks while also investigating ecological patterns and processes with fossil shark teeth. We link enameloid-bound nitrogen, and zinc isotope composition to trophic level and ‘clumped’ isotopes to the endothermy in Otodus megalodon in the Miocene – Pliocene. In addition, Eocene sand tiger teeth from Seymour Island, Antarctica, confirm warm waters and an early opening of the Drake Passage. Finally, the size distribution of fossil shark teeth in various Eocene localities suggests nearshore nurseries are an important habitat. The combined approach of geochemistry, morphology, and modeling allows the bridging of ecological concepts across extinct and extant sharks.

Sora Kim is an Assistant Professor at the University of California, Merced, in the Department of Life and Environmental Sciences. Her research focuses on ecological variability and the role of environmental conditions. She uses stable isotope techniques to translate patterns and processes between modern and ancient ecosystems. Many projects focus on different aspects of shark biology, but there are ongoing projects related to wolf competition and resource use, biogeochemical cycling in soils, and method development for stable isotope analysis. She is also active in programs and projects to increase belonging, access, justice, equity, diversity, and inclusion in the Geo- and Bio-sciences.

For the zoom information, please get in touch with Rey Garduño (rgarduno@stanford.edu)