radiolarian

American  

[rey-dee-oh-lair-ee-uhn] / ˌreɪ di oʊˈlɛər i ən /

noun

1. any minute, marine protozoan of the class Radiolaria, or, in some classification schemes, the superclass Actinopoda, having an amebalike body with radiating, filamentous pseudopodia and a usually elaborate outer skeleton.

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radiolarian British  

/ ˌreɪdɪəʊˈlɛərɪən /

noun

1. any of various marine protozoans constituting the order Radiolaria , typically having a siliceous shell and stiff radiating cytoplasmic projections: phylum Actinopoda (actinopods)

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radiolarian Scientific  

/ rā′dē-ō-lâr′ē-ən /

1. Any of various marine protozoans of the group Radiolaria, having rigid skeletons usually made of silica. The skeletons are usually spherically symmetrical and structurally complex, containing elaborate patterns of perforations (through which pseudopods extend) and often spicules. Skeletal remains of radiolarians sink to form ooze on the ocean floor, and prehistoric radiolarian ooze has fossilized to become chert and flint.

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Etymology

Origin of radiolarian

1875–80; < New Latin Radiolari ( a ) name of the group ( Latin radiol ( us ) a small beam, equivalent to radi ( us ) radius + -olus -ole ¹ + -aria -aria ) + -an

Example Sentences

And Sirjana correctly spelled puerilely — childish — and radiolarian — a single-celled marine animal having a spherical body with threadlike projections.

From Seattle Times • May 31, 2022

The shells of deceased diatoms and some radiolarian skeletons are also made of silicon dioxide.

From Scientific American • Apr. 15, 2013

When they die, their silicic, spherical skeletons sink to the ocean floor, form a radiolarian ooze.

From Time Magazine Archive

Some cherts contain tests of radiolaria, and correspond fairly closely to the siliceous radiolarian oozes which are gathering at the present day at the bottom of some of the deepest parts of the oceans.

From Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5 "Fleury, Claude" to "Foraker" by Various

"That mud," he said, "was dredged up from the bottom of the ocean, and every particle of it is the shell of a radiolarian."

From A History of Science, Volume 5(of 5) Aspects Of Recent Science by Williams, Henry Smith