Trophic position of Otodus megalodon and great white sharks through time revealed by zinc isotopes

Title	Trophic position of Otodus megalodon and great white sharks through time revealed by zinc isotopes
Authors	Jeremy McCormack, Michael L. Griffiths, Sora L. Kim, Kenshu Shimada, Molly Karnes, Harry Maisch, Sarah Pederzani, Nicolas Bourgon, Klervia Jaouen, Martin A. Becker, Niels Jöns, Guy Sisma-Ventura, Nicolas Straube, Jürgen Pollerspöck, Jean-Jacques Hublin, Robert A. Eagle, Thomas Tütken
Magazine	Nature Communications
Date	05/31/2022
DOI	10.1038/s41467-022-30528-9
Introduction	Diet is a vital aspect of an animal's lifestyle and ecological role. The trophic level of an organism signifies its functional position in an ecosystem, influencing its evolution and ecology. This study presents zinc isotopes (δ66Zn) as a tool for assessing trophic levels in various living and extinct sharks, including the Neogene megatooth shark (Otodus megalodon) and the great white shark (Carcharodon carcharias). We establish that dietary δ66Zn signatures are well-preserved in fossil shark tooth enameloid over geological timescales, serving as reliable indicators of each species' trophic level. We note notable δ66Zn variations among Otodus and Carcharodon populations, suggesting dietary changes during the Neogene. Interestingly, Early Pliocene C. carcharias and O. megalodon shared a comparable mean trophic level, offering insights into the extinction of the large Neogene megatooth shark.
Quote	Jeremy McCormack, Michael L. Griffiths and Sora L. Kim et al. Trophic position of Otodus megalodon and great white sharks through time revealed by zinc isotopes. Nat Commun. 2022. Vol. 13. DOI: 10.1038/s41467-022-30528-9
Element	Zinc (Zn)