ostracodes

Ostracodes are a diverse group of small crustaceans, commonly known as seed shrimp, that inhabit a wide range of aquatic environments, from freshwater lakes and rivers to brackish estuaries and the deep sea. They are characterized by their bivalved carapace, a shell-like covering composed of two hinged parts that completely enclose the body. This carapace is typically calcified and can vary greatly in shape, size, and ornamentation, making it useful for species identification and paleontological studies.

Ostracodes are found globally and have a long fossil record, dating back to the Ordovician period. Their ability to adapt to various salinity levels and temperatures has contributed to their widespread distribution. Many ostracode species are benthic, living on or in the sediment, while others are planktonic, drifting in the water column. Their diet is varied, including algae, detritus, and other small organisms.

Due to their abundance, widespread distribution, and excellent fossil preservation, ostracodes are valuable tools in paleontology and paleoenvironmental studies. Their carapaces can be used to reconstruct past oceanic conditions, such as salinity, temperature, and water depth, providing insights into Earth's history and climate change. They are also used in biostratigraphy for dating rock layers and in petroleum exploration as indicators of ancient depositional environments.