Emergence of modern marine ecosystems

The structure and function of marine ecosystems are not fixed. Instead, major innovations — from the origin of oxygenic photosynthesis, to the evolution of reefs or of deep bioturbation, to the rise of pelagic calcifiers — have changed biogeochemical cycles and ecosystem dynamics. As a result, modern marine ecosystems are fundamentally different from those in the distant past. In this Primer, Hull discusses the shifts in marine ecosystems that occurred during the latter part of the Mesozoic and how these revolutions have shaped modern ocean ecosystems.