Definition of coccolith in English:



  • A minute rounded calcareous platelet, numbers of which form the spherical shells of coccolithophores.

    • ‘The living cell possesses a gelatinous sheath in which are embedded calcareous plates termed coccoliths.’
    • ‘Like the rest of the world's seas, the Sargasso Sea has a population of the subsurface algae called coccoliths as well as planktonic foraminifera.’
    • ‘At this rate it is possible to produce an average 100 metre thickness of coccoliths as calcareous ooze on the ocean floor in less than 200 years.’
    • ‘Chalk, though it may include shell fragments, is predominantly composed of coccoliths from planktonic algae, forming fine-grained limestone.’
    • ‘The team did not limit themselves to foraminifera but used other planktonic groups such as the coccoliths and radiolaria.’


Mid 19th century: from Greek kokkos ‘grain or berry’ + lithos ‘stone’.