ra·​di·​o·​lar·​i·​an | \ ˌrā-dē-ō-ˈler-ē-ən \

Definition of radiolarian

: any of three classes (Acantharia, Polycystina, and Phaeodaria) of usually spherical chiefly planktonic marine protozoans having radiating threadlike pseudopodia and often a siliceous skeleton of spicules

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Other Words from radiolarian

radiolarian adjective

Examples of radiolarian in a Sentence

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The organic carbon decline coincided with the disappearance of more than 50 species of radiolarians, which served as a food source for numerous marine species and whose disappearance was an indicator of a major biological crisis. Reuters, WIRED, "Ancient Extinction Was Abrupt," 10 May 2001

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'radiolarian.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of radiolarian

1869, in the meaning defined above

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The first known use of radiolarian was in 1869

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