Until Now
BiologyEnvironmentGeology

Plankton take over the carbon cycle

Microscopic algae armoured in chalk plates begin raining carbonate into the deep ocean.

When
Known to
± 10 million years
Era
Jurassic, Mesozoic

Coccolithophores become ecologically dominant from the mid-Jurassic, and with diatoms and foraminifera they shift carbonate deposition from shallow shelves into the deep sea for the first time. This buffers ocean chemistry against acidification and fundamentally stabilises the long-term carbon cycle. Their accumulated skeletons later form the chalk of the Cretaceous — and the White Cliffs of Dover.

Just before

Just after