The end of the paleozoic era was signaled by

Mass extinction of land and water animals

Paleozoic era lasted for millions of years ago. It is divided in 6 different periods. It also signal various events in evolution which include the development of most invertebrate groups. Fish and fish like vertebrates arose from the early Paleoozoic and comprise more than 50 percent of the diversity of vertebrates that inhabits today. This period ended when the mass extinction of animals occured.