Topic: foraminiferan

foraminiferan , common name for members of the class Foraminifera, large, shelled ameboid protozoans belonging to the phylum Sarcodina. Most foraminiferan shells are calcareous, but some are siliceous, and others are built of sand grains. Initially, the shell contains a single chamber, and new chambers are added in a characteristic linear, spiral, or concentric series as the organism grows. Some shells reach several inches in diameter, but most species are less than a millimeter in diameter. Long, branching extensions of the cell (pseudopodia) reach from openings in the shell and fuse tog... Read more