Collection: Protists
by suzeroo
Unusual or remarkable protists. Radiolarians, acantharians and foraminiferans are single celled organisms within the broad category of protists. Foraminiferans build roundish shells made of calcium carbonate, while radiolarians and acantharians make silica or strontium skeletons in the shape of needles or shields. The calcium and silicate structures are very resistant and are called "tests".