Research overview: zinc isotopes and trophic level in fossil felids

This overview surveys the emerging use of zinc isotopes in tooth enamel as a tool for reconstructing the trophic level and diet of fossil cats. Unlike collagen-based carbon and nitrogen analysis, which is limited by the survival of protein, zinc isotopes are measured in mineral enamel that can persist far longer, extending dietary reconstruction to older and more degraded specimens. The ratio of zinc isotopes decreases up the food chain, allowing researchers to distinguish carnivores from herbivores and to compare the diets of predators such as sabertooths. The survey reviews the principles of the method, its application to extinct felids and their prey, and how it complements traditional isotopic proxies. It discusses why enamel-based zinc isotope analysis is opening new avenues for studying the feeding ecology of deep-time cats.