Permian

The last period of the Paleozoic era (after the Pennsylvanian), thought to have covered the span of time between 290 and 248 million years ago; also, the corresponding system of rocks. The Permian is sometimes considered part to the Carboniferous, or is divided between the Carboniferous and Triassic. It is named after the province of Perm, Russia, where rocks of this age were first studied.