|globigerina See also nummulite Often shortened to: foram any marine protozoan of the phylum Foraminifera, having a shell with numerous openings through which cytoplasmic processes protrude|
|[C19: from New Latin, from |
|foraminiferan (fə-rām'ə-nĭf'ər-ən) Pronunciation Key
Any of various chiefly marine protozoans of the order Foraminiferida or Foraminifera, having a body enclosed by a shell called a test and making up an important constituent of plankton. Perforations in a foraminiferan's test allow the protrusion of numerous long extensions (pseudopods), which form a net used to trap food. The tests of foraminiferans grow throughout the organism's life, and can exceed 5 cm (2 inches) in diameter. The tests of dead organisms form ooze found on the ocean floor. Extinct foraminiferans are important index fossils.
any unicellular organism of the rhizopodan order Foraminiferida (formerly Foraminifera), characterized by long, fine pseudopodia that extend from a uninucleated or multinucleated cytoplasmic body encased within a test, or shell. Depending on the species, the test ranges in size from minute to more than 5 cm (2 inches) in diameter and varies in shape, number of chambers, chemical composition, and surface orientation. Tests of a South Pacific species are large enough to be used as jewelry by oceanic islanders; Nummulite specimens from the Eocene limestones of the Egyptian pyramids often exceed 5 cm in diameter. Foraminiferans inhabit virtually all marine waters and are found at almost all depths, wherever there is protection and suitable food (microscopic organisms)
Learn more about foraminiferan with a free trial on Britannica.com.