The Collaborative International Dictionary
Coccolith
Coccolith \Coc"co*lith\, n. [Gr. ? a grain, seed + -lith.] (Biol.) One of a kind of minute, calcareous bodies, probably vegetable, often abundant in deep-sea mud.
Wiktionary
coccolith
n. (context biology English) A microscopic skeletal plate of calcite on the surface of certain marine phytoplankton; it forms chalk and limestone when fossilized
Wikipedia
Coccolith
Coccoliths are individual plates of calcium carbonate formed by coccolithophores (single-celled algae such as Emiliania huxleyi) which are arranged around them in a coccosphere.
Usage examples of "coccolith".
Eventually all the tiny foraminiferans and coccoliths and so on die and fall to the bottom of the sea, where they are compressed into limestone.