coccoliths The microscopic calcareous plates or discs, often oval and commonly intricately patterned and ornamented, that occur as part of the protective covering of a group of the unicellular algae called coccolithophorids. Coccoliths are a major component of the modern deep-sea calcareous oozes, and were especially abundant in the Mesozoic, particularly the Cretaceous Period, in which they became a major component of the Chalk lithology.

coccoliths The microscopic calcareous plates or discs, often oval and commonly intricately patterned and ornamented, that occur as part of the protective covering of a group of the unicellular algae called coccolithophorids. Coccoliths are a major component of the modern deep-sea calcareous oozes, and were especially abundant in the Mesozoic, particularly the Cretaceous Period, in which they became a major component of the Chalk lithology.

coccoliths The microscopic calcareous plates or discs, often oval and commonly intricately patterned and ornamented, that occur as part of the protective covering of a group of the unicellular algae called coccolithophorids. Coccoliths are a major component of the modern deep-sea calcareous oozes, and were especially abundant in the Mesozoic, particularly the Cretaceous Period, in which they became a major component of the Chalk lithology.