Definition of radiolaria in English:


plural noun

  • Radiolarians collectively.

    • ‘The importance of both stems from the fact that radiolaria and planktonic foraminifera live at or near the ocean surface and their shells incorporate a record of surface-water conditions as they grow.’
    • ‘The Nun Mine Member consists of thin-bedded calcareous mudstones locally with abundant radiolaria, and represents offshore, basinal environments.’
    • ‘As in other radiolaria, Acantharea have a gelatinous ectoplasm filled with vacuoles, separated from the inner cell mass by a fibrous capsular wall.’
    • ‘The marine biostratigraphy is based upon microfaunas and floras, notably planktonic foraminifera and radiolaria.’
    • ‘Fewer than 250,000 fossils - most are ‘large microbes,’: foraminifera, radiolaria, coccolithophores or diatoms - are named in the paleontological literature.’


Late 19th century: modern Latin (former order name), from late Latin radiolus ‘faint ray’, diminutive of radius ‘ray’.