Final period (299–251 Ma ago) of the Palaeozoic era, which is named after the central Russian province of Perm. The period is often noted for the widespread continental conditions that prevailed in the northern hemisphere and for the extensive nature of the southern hemisphere glaciation. Many groups of animals and plants, including the rugose corals (Rugosa), trilobites (Trilobita), and blastoid echinoderms (Blastozoa), vanished at the end of the Permian, in a mass extinction that was one of the great crises in the history of life. The period is divided into nine ages: the Asselian, Sakmarian, Artinskian, and Kungurian ages comprise the Cisuralian epoch; the Roadian, Wordian, and Capitanian ages comprise the Guadalupian epoch, and the Wuchiapingian and Changhsingian ages comprise the Lopingian epoch.
https://ucmp.berkeley.edu/permian/permian.php The Permian Period.