What does coccolith mean?
A coccolith is a microscopic plate made chiefly of calcium carbonate. These plates occur on the surfaces of coccolithophores, a group of marine plankton that are especially abundant in the world's oceans. When the plankton die, their plates sink and accumulate on the seafloor, where they can become part of sediment and eventually form limestone. Large populations of coccolithophores can create so-called coccolith blooms, visible through changes in water color and detectable through satellite imagery. In geology and paleontology, coccoliths are also valuable as fossils: their forms and characteristics can help scientists identify rock layers, reconstruct past ocean conditions, and date sediments. The word belongs primarily to specialist scientific and academic contexts rather than everyday speech, but it names the remarkably small structures responsible for both conspicuous ocean events and long-lasting geological deposits.
nounA minute, usually disk-shaped plate of calcium carbonate found on the surface of certain marine plankton called coccolithophores. Such plates may also be preserved as fossils in marine sediments.
- An individual calcareous plate forming part of the skeleton of a coccolithophore.
- A fossilized calcareous plate of this kind.
"The falling shells of coccolithophores left countless coccoliths in the ocean floor."
"Each coccolithophore carries dozens of overlapping coccoliths on its outer surface."
"Geologists identified coccoliths in the limestone and used them to date the sediment."
The standard plural is coccoliths. The word is normally countable when referring to individual plates or fossils.
"The scientist counted coccoliths from several sediment samples."
Microscopic coccoliths can form vast marine blooms and eventually become the calcium-carbonate grains of ancient limestone.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does coccolith come from?
The word combines Greek roots meaning “berry” or “seed” and “stone,” a reference to the small, rounded appearance of the plates. The first element also underlies scientific terms associated with rounded bodies, such as coccus and coccoid. The compound was developed for the calcareous plates produced by coccolithophores and was later extended to refer to their fossilized remains.
How coccolith is actually used
A specialized term used in marine biology, paleontology, sedimentology, and geology. It is usually countable and refers to individual plates rather than to the organism that produces them.
Easily confused with coccolith
A coccolith is an individual mineral plate, whereas a coccolithophore is the planktonic organism that produces and bears such plates.