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.