Foraminifera (Foraminifers) is a phylum of rhizarians. There are 42795 species of Foraminifers, in 3433 genera and 411 families. Dead Foraminifers formcalcareous oozes.
Definition: Calcareous ooze is a marine sediment composed primarily of the shells--also known as tests--of foraminifera, coccolithophores, and pteropods. This is the most common pelagic sediment by area, covering 48% of the world ocean's floor. This type of ooze is limited to depths above the Carbonate Compensation Depth at time of burial. It accumulates more rapidly than any other pelagic sediment type, with a rate that varies from 0.3 - 5 cm / 1000 yr.