Abstract
Ostracoda are small, bivalved crustaceans that have thrived on Earth for 500 million years. They inhabit marine and freshwater environments, and their well-preserved fossil record offers insights into past ecosystems and paleoenvironmental conditions. Ostracod shells, known as valves, are made of calcium carbonate or chitinous material, enclosing the body in two separate halves. The valves display diverse shapes and ornamentation, reflecting the wide variety of ostracod species. Internally, ostracods possess a developed musculature, antennae for sensing the environment and capturing food, mandibles for chewing, and maxillae for filtering food. Their body cavity houses the digestive, circulatory, and reproductive systems. Ostracod fossils are found in marine, lacustrine, and terrestrial deposits, providing opportunities to study their morphology, distribution, and evolution. Their rapid evolutionary rates and broad geographic distribution make ostracods valuable for biostratigraphy. By analyzing ostracod assemblages in fossil sediments, researchers can reconstruct ancient ecosystems and track environmental changes. Ostracods serve as indicators of environmental conditions such as water temperature, salinity, and oxygen levels. Studying ostracod fossils informs our understanding of past environments and climate change.