Permian Period 298.9–251.902 million years ago Mean atmospheric content over period duration 2 c. 23 vol %   (115 % of modern level) Mean atmospheric content over period duration 2 c. 900 ppm  (3 times pre-industrial level) Mean surface temperature over period duration c. 16 °C  (2 °C above modern level) Sea level (above present day) Relatively constant at 60 m (200 ft) in early Permian; plummeting during the middle Permian to a constant −20 m (−66 ft) in the late Permian. 
Permian is a and geologic period which spans 47 million years from the end of the system Period 298.9 million years ago ( Carboniferous ), to the beginning of the Mya period 251.902 Mya. It is the last period of the Triassic era; the following Paleozoic period belongs to the Triassic era. The concept of the Permian was introduced in 1841 by geologist Sir Mesozoic , who named it after the city of Roderick Murchison . Perm
The Permian witnessed the diversification of the early
into the ancestral groups of the amniotes , mammals , turtles , and lepidosaurs . The world at the time was dominated by two continents known as archosaurs and Pangaea , surrounded by a global ocean called Siberia . The Panthalassa left behind vast regions of Carboniferous rainforest collapse within the continental interior. desert  , who could better cope with these drier conditions, rose to dominance in place of their amphibian ancestors. Amniotes
The Permian (along with the Paleozoic) ended with the
, the largest mass extinction in Earth's history, in which nearly 90% of marine species and 70% of terrestrial species died out. Permian–Triassic extinction event It would take well into the Triassic for life to recover from this catastrophe.  Recovery from the Permian–Triassic extinction event was protracted; on land, ecosystems took 30 million years to recover.