← All periods

What did Earth look like in the Silurian? (444–419 Ma)

Warm shallow seas spread widely; jawed fish appeared along with the first land animals and vascular plants.

Explore the Silurian Earth in 3D →

Key events of this period

  • Ordovician Extinction

    444 Ma

    The second-largest mass extinction, eliminating ~85% of marine species. Likely caused by rapid glaciation as Gondwana drifted over the South Pole.

  • Evolution of Jaws

    430 Ma

    Jawed fish (gnathostomes) evolved in the Silurian. The invention of jaws revolutionized feeding strategies and became a key driver of vertebrate diversification.

  • Caledonian Orogeny

    420 Ma

    Ancient mountains formed by the collision of Laurentia, Baltica, and Avalonia, closing the Iapetus Ocean. Remnants survive today in Scotland, Scandinavia, and Newfoundland, forming the foundation of the Laurussian landmass.