Definition

Noun: A type of microscopic, single-celled marine protozoan belonging to the class Radiolaria. Radiolarians are characterized by having a central capsule that divides the cell into inner and outer portions, and they produce intricate, beautiful skeletons made of silica (glass). They move and capture food using slender, radiating projections called pseudopods.

Usage

The word "radiolarian" is used as a countable noun to refer to an individual organism or the group as a whole. It is a scientific term used primarily in biology, marine science, and paleontology. - The ocean sediment sample was rich in radiolarian fossils. - Under the microscope, the radiolarian's delicate silica skeleton was clearly visible.

Advanced Usage

• Radiolarian ooze: A deep-sea sediment composed largely of the siliceous skeletons of radiolarians.
  • The seafloor in that region is covered by radiolarian ooze.

Variants and Related Words

• Radiolaria (noun, plural): The taxonomic class name for all radiolarians.
  • Radiolaria are an important component of marine plankton.

Synonyms

• Marine protozoan: A general term for single-celled organisms in the ocean, which includes radiolarians.
• Siliceous plankton: Plankton with silica-based structures, including radiolarians and diatoms.

Noun

1. protozoa with amoeba-like bodies and radiating filamentous pseudopods