1. A geological era from about 541 million to 252 million years ago, characterized by the evolution of marine invertebrates, fish, amphibians, and early reptiles
   - Paleozoic era, Palaeozoic [Brit, Cdn]

1. Of or relating to or denoting the Paleozoic era
   "Paleozoic fossils provide crucial information about the evolution of early life forms";
   - Palaeozoic [Brit, Cdn]

Type of: era, geological era

Encyclopedia: Paleozoic