Paleozoic, Paleozoic era

from 230 million to about 544 million years ago

• era, geological era — a major division of geological time; an era is usually divided into two or more periods

• Permian, Permian period — from 230 million to 280 million years ago; reptiles
• Carboniferous, Carboniferous period — from 280 million to 345 million years ago
• Devonian, Devonian period, Age of Fishes — from 345 million to 405 million years ago; dominance of fishes and appearance of amphibians and ammonites
• Silurian, Silurian period — from 405 million to 425 million years ago; first air-breathing animals
• Ordovician, Ordovician period — from 425 million to 500 million years ago; conodonts and ostracods and algae and seaweeds
• Cambrian, Cambrian period — from 500 million to about 544 million years ago; marine invertebrates