The climate of the Paleozoic Era varied as the period began with large glaciers covering the surface of the Earth, which gave way to warmer temperatures, glacial melt and volcanic activity. The Paleozoic Era existed 545 to 248 million years ago. Increasing frequency and power of volcanic eruptions drew the once-separate continents of Earth closer together and warmed land and sea temperatures, leading to an abundance of life forms.
Glacial coverage and retreat reshaped the Earth's surface. New land forms emerged, and with the help of tectonic plates and volcanic activity, distances between continents closed. Tectonic activity, in fact, caused the merger of existing landforms into a large continent, called Pangaea. Glaciers formed approximately 430 million years ago. They moved far south, reaching the continent of present-day Africa. During the Paleozoic Era, Africa extended down to the South Pole. As with large continents today, the continent Pangaea experienced variations in seasonal and long-term weather patterns and atmospheric conditions. The interior region consisted primarily of dry land and air, resembling desert regions. The gradual warming throughout the later periods of the Paleozoic Era introduced monsoons, which affected regional climates. Fossils collected from the Paleozoic Era indicate many life forms of invertebrate and vertebrate species arose during that time. Vertebrates including fish, amphibians and reptiles emerged; along with plants, early animals lived in water and on land.