Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
Tonian Period
Introduction & Top Questions References & Edit History Related Topics
Images
A chart showing the Proterozoic eon on the geologic time scale, divided into Paleoproterozoic, Mesoproterozoic, and Neoproterozoic eras with their respective periods and the millions of years ago each period began, ranging from 2,500 to about 539 million years ago. A detailed geologic time scale chart displaying Earth's history from the Hadean Eon over 4.5 billion years ago to the present, organized by eons, eras, periods, epochs, and ages with color-coded columns and corresponding dates in millions of years.
Related Questions

Tonian Period: References & Edit History

Article Contributors

Primary Contributors

  • John P. Rafferty
    John P. Rafferty writes about Earth processes and the environment. He serves currently as the editor of Earth and life sciences, covering climatology, geology, zoology, and other topics that relate to the natural world.

Other Contributors

  • Kenneth Wilks

Article History

Type Description Contributor Date
Noted that some evidence exists to suggest that the first animals could have emerged between 800 million and 700 million years ago. Oct 16, 2026
Added cross-references. Jan 27, 2023
Noted that green algae and seaweed first appeared during the Tonian Period. Dec 09, 2020
New article added. Oct 18, 2016
View Changes:
Article History
Revised:
By: