Scanning Electron Micrograph of various Radiolarians. Radiolarians are amoeboid protozoa that produce intricate mineral skeletons. They are found as zooplankton throughout the ocean, and their skeletal remains cover large portions of the ocean bottom as radiolarian ooze. Geologists at Scripps Institution of Oceanography, University of California, San Diego study the evolution of these microfossils as a basis for assigning ages to ocean sediments. Magnified 350X at 8x10".