==== Radiolaria ====

{{:diatoms02.jpg?nolink|}}

  * single-celled animals (“protista”), like forams but with a siliceous shell
  * geologic range: Precambrian – Recent
  * a planktonic mode of life, in fully marine settings
  * biostratigraphically significant in particular areas/intervals but subordinate to other fossil groups and therefore has relatively few practicing specialists
  * can be significant in sediments deposited below the CCCD

{{:radiolaria01.jpg?nolink|}}   {{:radiolaria02.jpg?nolink|}}

//Left: Assorted radiolaria; some of the most beautiful microorganisms in the oceans. Right: The living radiolarian is very similar to the planktonic foram.//