Ledringhem Paleozoic era. Euramerica, also known as Laurussia, was a minor supercontinent created in the Devonian as the result of a collision between the Laurentian, Baltica, and Avalonia cratons. Euramerica became a part of the major supercontinent Pangaea in the Permian. In the Jurassic, when Pangaea rifted into two continents, Gondwana and Laurasia, Euramerica was a part of Laurasia. 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. Ledringhem lies on the London-Brabant Massif,
Gondwana Late Triassic and became important in the Jurassic and Cretaceous. It is possible that gymnosperm biodiversity surpassed later angiosperm biodiversity and that the evolution of angiosperms began during the Triassic but, if so, in Laurasia rather than in Gondwana. Two Gondwanan classes, lycophytes and sphenophytes, saw a gradual decline during the Triassic while ferns, though never dominant, managed to diversify. The brief period of ice house conditions during the Triassic–Jurassic extinction event had a dramatic impact on dinosaurs but left plants largely unaffected. The Jurassic was mostly one of hot house conditions and, while vertebrates managed to diversify in this