Definition of nummulite in English:



  • The flat disc-shaped calcareous shell of a foraminiferan (single-celled planktonic animal), found commonly as a fossil up to 8 cm across in marine Tertiary deposits.

    • ‘The occurrence higher in the succession of nummulites and neritic fossils indicates overall shallowing upwards.’
    • ‘Well-rounded clasts include lava, volcaniclastic sandstones and bioclastic limestones with nummulites, bryozoa, microbial carbonate and bivalve material.’
    • ‘In the seas, the calcareous nannofossils were still in evidence but in shallow waters the benthonic nummulite and other larger foraminifera became very abundant.’
    • ‘They found that the Eocene nummulites lived in nutrient-rich environments during a warm climatic phase.’


Early 19th century: from Latin nummulus (diminutive of nummus coin) + -ite.