Archaean
(Science: geology) The earliest period in geological period, extending up to the Lower silurian. It includes an azoic age, previous to the appearance of life, and an eozoic age, including the earliest forms of life.
this is equivalent to the formerly accepted term azoic, and to the eozoic of Dawson.
Dictionary > Archaean
You will also like...
![](https://www.biologyonline.com/wp-content/uploads/2020/09/Community-Patterns-300x168.jpg)
Community Patterns
Learn about community patterns and the ecological factors influencing these patterns. Revisit some of the ecosystems you..
![Biosecurity and Biocontrol](https://www.biologyonline.com/wp-content/uploads/2020/09/Biosecurity-and-Biocontrol-300x168.jpg)
Biosecurity and Biocontrol
This lesson explores the impact of biosecurity threats, and why they need to be identified and managed. Examples to incl..
![Lotic community of algal species](https://www.biologyonline.com/wp-content/uploads/2020/02/Lotic-Communities-Algae-252x168.jpg)
Lotic Communities & Algae
Lotic communities have conditions that are rather harsh for typical plants. Thus, the diversity of plant species in loti..
![takahē](https://www.biologyonline.com/wp-content/uploads/2020/09/takahe-300x168.jpg)
Takahē (Porphyrio hochstetteri)
Meet the colorful takahē, an extremely rare flightless bird. Find out more about its unique features and why they matte..
![Still Water Community Plants](https://www.biologyonline.com/wp-content/uploads/2020/02/Still-Water-Community-Plants-252x168.jpg)
Still Water Community Plants
This tutorial looks at the adaptations of freshwater plants for them to thrive in still water habitats. Familiarize your..
![An artist depiction of a Precambrian multicellular life form.](https://www.biologyonline.com/wp-content/uploads/2020/02/The-Evolution-of-Cell-Organelles-224x168.jpg)
The Evolution of Cell Organelles
The nucleus containing the genetic material, DNA, and the mitochondria, well-identified as the "powerhouse of the cell",..