Planktonic foraminifera

Planktonic foraminifera are tiny, single-celled marine organisms with flexible shells called tests, often made of calcium carbonate. They float in the upper layers of the ocean, drifting with currents. These microorganisms are important for understanding Earth's history because their shells settle on the seafloor after they die, forming layers used by scientists to study past climates and ocean conditions. Their diverse shell shapes and compositions also help researchers interpret changes in ancient environments over millions of years.