Browsing the "Silurian" Category

The Silurian period is a division of earth’s history spanning from around 443 to 419 million years ago, and during which the first land ecosystems were established. Plants began to cover the continents, which in turn made the land habitable for arthropods such as the arachnid-like trigonotarbids. In the oceans, arthropods reached enormous sizes with sea scorpions over 2 meters long. Vertebrates continued to diversify and the first bony fish appeared. The climate during the Silurian was warm, with sea levels reaching 140 meters above present. At the end of the Silurian, the Iapetus Ocean finally closed resulting in the collision of the supercontinents Laurentia and Gondwana. This collision formed the Caledonian and Appalachian mountains (which at the time were much closer together, forming a continuous mountain chain).