radiolarian

[rey-dee-oh-lair-ee-uh n]

noun

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.

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 -ole¹ + -aria -aria) + -an

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Examples from the Web for radiolarian

Historical Examples of radiolarian

Most of these Radiolarian marls appear to date from the middle Tertiary (Miocene) period, and to be deep-sea formations.
Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia)
Ernst Haeckel
We unite here all these skeletonless Radiolarian colonies into one single genus Collozoum, constituted in my Monograph (p. 522).
Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia)
Ernst Haeckel
In several cases the character of the Radiolarian fauna at different depths presented characteristic differences.
Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia)
Ernst Haeckel
A larger number of new forms has been found in the Radiolarian ooze collected by the Challenger, and others fossil in Barbados.
Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index
Ernst Haeckel
This remarkable species is the oldest known skeleton of a Radiolarian, a figure of it being given in 1838, loc.
Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index
Ernst Haeckel

British Dictionary definitions for radiolarian

radiolarian

noun

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

Word Origin for radiolarian

C19: from New Latin Radiolaria, from Late Latin radiolus little sunbeam, from Latin radius ray, radius

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for radiolarian

1862, from Radiolaria, Modern Latin classification name, from Latin radiolus, diminutive of radius (q.v.).

radiolarian in Science

radiolarian

[rā′dē-ō-lâr′ē-ən]

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.