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Wetland plants, geysers and volcanoes during the Silurian period

Silurian period

The Silurian period was the time when reefs got their act together, grew really big and created a completely new type of ecosystem for marine life. Silurian reefs weren't built by the same types of coral around now, but by a host of tabulate and rugose corals, crinoids and sponges. As the Ordovician ice ages ended, sea levels rose, making the Silurian a period of extensive seas. Bony fish made their first appearance. Meanwhile, on land, plants became more established, and grew in a zone along the edges of rivers and lakes to give Earth its first riverine and wetland habitats.

Began: Ordovician-Silurian mass extinction
443 million years ago

Ended: 417 million years ago

What the Earth was like

A map of the Earth in the Archean Era

Reconstruction of the Earth in the Archean era, 3.8 billion - 2.5 billion years ago. Credit: Dr Ron Blakey, NAU Geology.

Causes of extinctions

During this period the following extinction level events are thought to have occurred.

Climate change Climate change
Earth's climate is not constant. Over geological time, the Earth's dominant climate has gone from ice age to tropical heat and from steamy jungles to searing deserts.

Types of fossils formed in this period

Exceptional preservation
Exceptional preservation Trace fossils
Trace fossils

About

The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.4 ± 1.5 million years ago (mya), to the beginning of the Devonian Period, about 419.2 ± 3.2 mya (ICS, 2004). As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by several million years. The base of the Silurian is set at a major extinction event when 60% of marine species were wiped out. See Ordovician-Silurian extinction events.

A significant evolutionary milestone during the Silurian was the appearance of jawed and bony fish. Life also began to appear on land in the form of small, moss-like, vascular plants which grew beside lakes, streams, and coastlines. However, terrestrial life would not greatly diversify and affect the landscape until the Devonian.

Read more at Wikipedia

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Geological time

  1. Origin of the Earth 4.6 billion years ago
  2. Archean era
  3. Cryogenian period
  4. Ediacaran period
  5. Cambrian period
  6. Ordovician period
  7. Silurian period
  8. Devonian period
  9. Carboniferous period
  10. Permian period
  11. Triassic period
  12. Jurassic period
  13. Cretaceous period
  14. Palaeocene epoch
  15. Eocene epoch
  16. Oligocene epoch
  17. Miocene epoch
  18. Pliocene epoch
  19. Pleistocene epoch
  20. Holocene epoch
  21. Present day

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