Foraminifera are tiny, single-celled organisms found in marine environments. They belong to the group of protists and are characterized by their intricate shells, called tests, which can be made of calcium carbonate or silica. These shells come in various shapes and sizes, often resembling tiny, ornate structures. Foraminifera play a crucial role in the ocean ecosystem. They serve as important indicators of environmental conditions and are used in paleoclimatology to study past climate changes. Their fossilized remains are commonly found in sedimentary rocks, helping scientists understand Earth's geological history.