Phanerozoic is a geological era that includes the last 541 million years, characterized by the proliferation of complex animal and plant life. Synonyms for Phanerozoic era include the time of visible life, the age of animals or the era of macroscopic organisms. It is also synonymous with the "Visible Eon" or the "Vegetable and Animal Age." The Phanerozoic is divided into three extensive periods, each characterized by significant geological events. These periods are further subdivided into smaller intervals, and each of these has its own set of synonyms. These include the Paleozoic Era (ancient life), the Mesozoic Era (middle life), and the Cenozoic Era (recent life).