The Paleozoic Era, meaning "ancient life," is the earliest era of the Phanerozoic Eon, spanning from roughly 541 to 252 million years ago. It's characterized by the diversification of life, particularly in the oceans, and the eventual colonization of land by plants and animals. The era is marked by significant geological and biological changes, including the formation and breakup of supercontinents and the evolution of diverse life forms, culminating in the largest mass extinction in Earth's history.