Earth and Environment Atlas

How The Planet Works
Sign In
Text size
100%
Theme

Switch Atlas

The Inner World

The Civil World

The Natural World

Eras

Ordovician

or-duh-VISH-ee-un

Citation Formats

General Reference

APA Style

BibTeX

The Ordovician is the second period of the Paleozoic Era, following the Cambrian and preceding the Silurian, spanning roughly 486.85 to 443.1 million years ago. Marine life diversified enormously during the Great Ordovician Biodiversification Event, but the period closed with the Ordovician-Silurian extinction, the second-largest mass extinction in Earth history.

Facts
Rank
Period 1
Start (Million Years Ago)
486.85 1
Standard boundary age from the ICS International Chronostratigraphic Chart; not independently re-dated by this atlas.
End (Million Years Ago)
443.1 1
Standard boundary age from the ICS International Chronostratigraphic Chart; not independently re-dated by this atlas.
Key Event
The Ordovician-Silurian extinction events at the period's close eliminated about 49 percent of marine genera, with brachiopods, bryozoans, trilobites, conodonts and graptolites especially hard hit. 1
Cross-Tradition Connections

Part Of

Paleozoic, Eras
Sources
1. Ordovician (Wikipedia)
Wikimedia FoundationIntroduction
Quote, Introduction
Life continued to flourish during the Ordovician as it had in the earlier Cambrian Period, although the end of the period was marked by the Ordovician-Silurian extinction events.
View the Source
1. Ordovician (Wikipedia)
Wikimedia FoundationEnd of the Ordovician
Quote, End of the Ordovician
about 49% of genera of fauna disappeared forever; brachiopods and bryozoans were greatly reduced, along with many trilobite, conodont and graptolite families.
View the Source
1. Ordovician (Wikipedia)
Wikimedia FoundationClimate
Quote, Climate
The Early Ordovician climate was very hot, with intense greenhouse conditions and sea surface temperatures comparable to those during the Early Eocene Climatic Optimum.
View the Source
1. Ordovician (Wikipedia)
Wikimedia FoundationClassificationView the Source
1. Ordovician (Wikipedia)
Wikimedia FoundationTimespan (start)View the Source
1. Ordovician (Wikipedia)
Wikimedia FoundationTimespan (end)View the Source
Comments (0)
No comments yet. Be the first to share a thought.
Reader Challenges (0 open reader challenges)
No disputes yet. Spotted an error or a better source? Open the first one.

View At A Past Year

The atlas records no dated fact of its own for this entry, so there is no other year to choose.