Continent a period of 2.0–1.8 billion years ago and broke up about 1.5–1.3 billion years ago. The supercontinent Rodinia is thought to have formed about 1 billion years ago and to have embodied most or all of Earth's continents, and broken up into eight continents around 600 million years ago. The eight continents later re-assembled into another supercontinent called Pangaea; Pangaea broke up into Laurasia (which became North America and Eurasia) and Gondwana (which became the remaining continents). The following table lists the seven continents with their highest and lowest points on land, sorted in decreasing highest points. † The lowest
Gondwana and barren landscape. West Gondwana drifted north during the Devonian which brought Gondwana and Laurasia close together. Global cooling contributed to the Late Devonian extinction (19% of marine families and 50% of genera went extinct) and glaciation occurred in South America. Before Pangaea had formed terrestrial plants, such as pteridophytes, began to diversify rapidly resulting in the colonisation of Gondwana. The Baragwanathia Flora, found only in the Yea Beds of Victoria, Australia, occurs in two strata separated by or 30 Ma; the upper assemblage is more diverse and includes Baragwanathia, the first primitive herbaceous lycopod to evolve from the zosterophylls.