Ostracods

Part of speech: noun

Definitions

1. A type of small crustacean typically found in aquatic environments, known for their bivalve-like shell and often studied in geological and paleontological contexts
2. Microscopic aquatic creatures belonging to the class Ostracoda, notable for their distinct shells and habitats ranging from marine to freshwater ecosystems
3. Tiny crustaceans encased in a two-part shell, prevalent in various water bodies, often serving as important indicators in environmental and geological research

Etymology: The plural of "ostracod," these animals are tiny crustaceans, typically a millimetre or less long, that live in nearly every kind of water, from the open ocean to ponds and groundwater. Their name comes from the Ancient Greek "óstrakon," which meant a piece of broken pottery or a shell, and the adjective "ostrakṓdēs" meant "covered with shell." The creatures are named for the two hinged valves that enclose their bodies, which look like a tiny bivalve clam. The shell is the key to the name, and the Greek word itself had a double life. "Óstrakon" was used for a fragment of clay pot, and that same word gave us "ostracism," because Athenians scratched names onto broken pottery shards to vote a citizen into exile. The Greek word for a shard and the word for a shell were thus the same, and scientists reached for it when they needed a label for animals with a clamshell-like covering.