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Plants & CreaturesGreekEnglish

Ostracod

/ˈɒstrəkɒd/noun

A tiny crustacean whose body is enclosed in a hinged two-part shell, abundant in fresh water and the sea.

The Greek roots

ὄστρακον
óstrakon
shell, potsherd

Literally: shelled one

The story of the word

The root is the potsherd Athenians scratched a name onto when voting a man into exile, which is why ostracism and this seed-sized crustacean are relatives. Their hinged carapaces fossilise beautifully, so oil geologists date rock layers by them. Some deep-sea species squirt clouds of blue light when attacked, and Japanese soldiers once read maps by crushing dried ones in wet palms.

How it travelled
Ancient Greek → scientific Latin → English
First recorded
19th century

Same family

ostracismoysterosteology

In a sentence

A single core sample held thousands of ostracod valves.

Ostracods flicker across the tank whenever the light moves.

Built on the same root

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