Abstract – Fish are the most diverse group of vertebrates on the planet today, and the type and abundance of fish present in the marine ecosystem depends on the environmental conditions and food web processes in that region. Ichthyoliths – isolated microfossil fish teeth and shark scales – preserve a unique history of the abundance, community composition, and evolutionary history of fish. In this talk, I draw on the 55+ year legacy of interdisciplinary and collaborative foundational work supported by scientific ocean drilling and ichthyoliths preserved in deep-sea sediments to explore how open-ocean fish and sharks respond to Cretaceous and Cenozoic global change, from mass extinctions to rapid climate change events, and discuss for how these upper trophic level marine vertebrates interact with the dynamic earth system.