Permian Period was a time in Earth’s history that lasted from around 299 million to 252 million years ago. The period is named for the town of Perm, Russia, where geologists first studied rocks of this age. Today, the best-known Permian Period rocks come from western Texas, southern China, and the Karoo region of South Africa. The Permian Period was the last period of the Paleozoic Era, a time in which early living things left behind an abundance of fossils.
During the Permian Period, most of Earth’s land formed a giant continent called Pangaea. This arrangement left vast areas of land far from the coast. Little rain fell in the continent’s interior, and deserts were widespread. Shallow marine areas existed only along the coasts of Pangaea and in a few large inland seas. See Earth (History of Earth).
Despite the dry conditions inland, plants and animals began spreading into the continental interior. Before the Permian Period, most life on land was limited to wet areas, such as riverbanks and swamps. During the period, many living things evolved (developed gradually) in ways that reduced their dependence on water. New organisms better adapted for life on dry land included the first animals to lay hard-shelled eggs and the first seed plants, relatives of modern conifers(plants that bear seeds in cones).
By the later Permian Period, plant and animal communities had become more varied. Animals evolved to fill a growing number of ecological niches. An ecological niche is the role an organism plays in a community of living things. Animals developed into small insectivores (insect eaters), herbivores (plant eaters) of various sizes, and a range of predators (animals that prey on other animals). The dominant animals of the Permian Period were synapsids. Certain synapsids became the ancestors of mammals, and they had some mammalian characteristics. The best-known Permian synapsid is Dimetrodon, a large carnivore with a tall, saillike fin on its back.
Most types of Permian life disappeared completely during the period’s last few thousand years. This event, called the Permian extinction, was the most devastating extinction event in Earth’s history. Scientists debate the extinction’s cause. Many scientists suspect it resulted from massive volcanic eruptions that occurred at the time in what is now western Siberia. Some time after the Permian extinction, the dinosaurs appeared and soon became the dominant land animals.
