Permian Period, in geologic time, the last period of the Paleozoic Era. The Permian Period began 298.9 million years ago and ended 252.2 million years ago, extending from the close of the Carboniferous Period to the outset of the Triassic Period. At the beginning of the period, glaciation was widespread, and latitudinal climatic belts were strongly developed. Climate warmed throughout the Permian times, and, by the end of the period, hot and dry conditions were...