Silurian Period

An age of land plants and fish diversification

The Silurian Period (443-419 Ma) is in the Paleozoic Era, occurring after the Ordovician Period and before the Devonian Period.

Geologic Age

  • 443.8–419.2 million years ago


What happened during this time?


  • The climate changes dramatically during this Period

    • The early Silurian was a time of global ice-house climate that included great ice sheets at high latitudes

    • During the middle of Llandovery the climate becomes warmer

    • The world during this time has distinct north-south climatic zones

  • Plate tectonic activity shifts continents

    • Gondwana drifted farther across the South Pole

    • Siberia, Laurentia, and Baltica clustered around the equator.

    • Laurentia and Baltica collided at the end of the Silurian, forming a new supercontinent, Euramerica, and raising new mountain ranges.

  • Formation of extensive evaporite (salt) deposits near the equator.

  • Large glacier melt and sea levels rise

  • Nearly continuous sea from New York to Nevada, and other shallow seas still covered parts of other continents

  • Mean oxygen levels in the atmosphere: 19%

  • Mean carbon dioxide levels in the atmosphere: 4,600 ppm

  • The earliest record of fire on Earth from 430 Ma (Glasspool & Gastaldo 2022)




  • Diversification of land fungi

    • Tortotubus protuberans, a possible land-dwelling fungus from 440 Ma sediments in Sweden (Smith 2016).


  • Coral reefs first appear

  • Relatives of spiders, scorpions, millipedes and centipedes first appear

    • The first flying insects probably appear during this time

  • Evolution of fishes; diversification of jawless fish

Eon / Era