os·​tra·​cod ˈä-strə-ˌkäd How to pronounce ostracod (audio)
variants or less commonly ostracode
: any of a subclass (Ostracoda) of very small aquatic crustaceans that have the body enclosed in a bivalve carapace, the body segmentation obscured, the abdomen rudimentary, and only seven pairs of appendages

Examples of ostracod in a Sentence

Recent Examples on the Web So there’s branchiopods, ostracods, copepods, cladocerans...and besides the crustaceans, there’s a lot more. Christopher Intagliata, Scientific American, 3 May 2023 The ostracod – and countless other small fossils – cannot be seen adequately using microscopes, however, so their mineral tomb has to be gradually ground away and the fossil recreated with 3-D digital imaging. Liam Herringshaw, Discover Magazine, 27 July 2015 Ghoulish in appearance, creatures like this ostracod have thrived for millennia as little more than floating heads. Discover Magazine, 17 Nov. 2016 Discovered in a ditch near the Anglo-Welsh border in the early 2000s, a fossilized ostracod, or seed shrimp, proved to be quite clearly male. Liam Herringshaw, Discover Magazine, 27 July 2015 Bioluminescent ostracod crustaceans, like tiny fireflies of the sea, have a gland that makes their bioluminescent goo. Quanta Magazine, 16 Aug. 2021 Although giant in name and more than 30 times the size of the average ostracod, this species is still only around an inch long. Thomas Page, CNN, 2 July 2021 Researchers had previously described ostracod sperm from fossils found in Romania, but those dated back to less than 15,000 years ago. Daniel Cressey, Scientific American, 14 May 2014 Scientists announced the discovery of giant sperm inside a female ostracod trapped in Burmese amber. Rafil Kroll-Zaidi, Harper's Magazine, 24 Nov. 2020 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'ostracod.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


from the base of New Latin Ostracoda, neuter plural, borrowed from Greek ostrakṓdēs "like an earthern pot (of a crab shell), testaceous," from óstrakon "earthen vessel, potsherd" + -ōdēs "having the qualities of" (originally, "smelling of," s-stem adjective from the base of ózein "to smell, give off an odor," as in anthemṓdēs "smelling like flowers" > "flowery, blooming") — more at ostracon, odor

First Known Use

1865, in the meaning defined above

Time Traveler
The first known use of ostracod was in 1865

Dictionary Entries Near ostracod

Cite this Entry

“Ostracod.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ostracod. Accessed 23 Sep. 2023.

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