The Paleontology of North America

Radiolarians from North America

What are Radiolarians? Radiolarians are unicellular protists that build external, glassy skeletons (tests) of silica. Their intricate tests come in various shapes and often have delicate spikes and projections that help increase buoyancy. Most radiolarians live as single cells, but some form long colonies up to 1 meter long. Radiolaria are members of the marine plankton, floating around the ocean at the whim of currents.

First known fossil occurrence: Cambrian.

Last known fossil occurrence: Quaternary. This group has living relatives.

Fossils through time:
Choose a time period to see what life was like:

Quaternary
Tertiary
Cretaceous
Jurassic
Triassic
Permian
Carboniferous
Devonian
Silurian
Ordovician
Cambrian
Precambrian