Euramerica (also known as Laurussia – not to be confused with Laurasia, – the Old Red Continent or the Old Red Sandstone Continent) was a minor supercontinent created in the Devonian as the result of a collision between the Laurentian, Baltica, and Avalonia cratons during the Caledonian orogeny, about 410 million years ago. In the Late Carboniferous, tropical rainforests lay over the equator of Euramerica. A major, abrupt change in vegetation occurred when the climate aridified. The forest fragmented and the lycopsids which dominated these wetlands thinned out, being replaced by opportunistic ferns. There was also a great loss of amphibian diversity and simultaneously the drier climate spurred the diversification of reptiles.
In the Cretaceous, Laurasia split into the continents of North America and Eurasia. The Laurentian craton became a part of North America while Baltica became a part of Eurasia, and Avalonia was split between the two.