The famous supercontinent Pangea has been divided into four main stages: Permian, Triassic, Jurassic and Cretaceous. This article will outline the main events or main ideas of what happened during each period. The Permian Period The Permian Period was the last period of the Paleozoic Era, spanning from approximately 299 million years ago to 251 million years ago. This period affected many different organisms from many different environments, but it primarily affected marine life; specifically invertebrates. Some groups survived the Permian mass extinction at extremely small numbers, but they will never achieve the ecological dominance they once had. Say no to plagiarism. Get a Custom Essay on “Why Violent Video Games Should Not Be Banned”?Get the original essay On land, a smaller extinction occurred, eliminating many diapsids and synapsids, making way for other species to dominate, what is now known as "The Age of Dinosaurs". In plant life, forests of fern-like plants called gymnosperms, plants whose offspring are enclosed in seeds. The Permian period was a time of major change, and Earth was never the same afterward. The Triassic Period The Triassic Period began at the end of the Paleozoic Era and the beginning of the Mesozoic Era, which lasted from approximately 254 million years ago to 206 million years ago . Pangea only began to break up in the mid-Triassic period, forming Gondwana (South America, Africa, India, Antarctica and Australia) to the south and Laurasia (North America and Eurasia-Europe and Asia) to the north. The movements that created these two supercontinents were due to seafloor spreading at the mid-ocean ridge located at the bottom of the Tethys Sea, the body of water between Gondwana and Laurasia. As Pangea broke apart, mountains began to form on the west coast of what would eventually become North America by subduction of ocean plates beneath continental plates. Toward the end of the Triassic, mountains continued to form along the coast from Alaska to Chile. While mountains were forming in North and South America, North Africa was separated from Europe by the growing divide. This division of continents began to move westward, eventually separating eastern North America from North Africa. The Jurassic Period The Jurassic period was the second part of the Mesozoic era. This occurred between 199.6 and 145.5 million years ago. During the Jurassic period, Pangea divided. The northern half, known as Laurentia, divided into masses that would eventually form North America and Eurasia, creating spaces for the central Atlantic and the Gulf of Mexico. The southern half, called Gondwana, drifted toward an eastern segment that would form Antarctica, Madagascar, India and Australia, and a western portion that would form Africa and South America. This separation, along with warmer global temperatures, allowed for the diversity and dominance of dinosaurs. Dinosaurs may have been the dominant land animals, but they weren't the only ones. Early mammals were mostly small herbivores or insectivores and did not compete with larger reptiles. Adelobasileus, a shrew-like animal, possessed the differential ear and jaw bones of a mammal and dates to the late Triassic. The Cretaceous Period The Cretaceous Period was the last and longest part of the era.