1. of, relating to, or denoting the geological era between the Precambrian and Mesozoic eras, lasting from about 541 to 252 million years ago
Usage: geological term; capitalized

1. the Paleozoic era or the rocks and fossils formed during this time period
Usage: geological term; capitalized

Examples

• The Paleozoic era saw the emergence of most major animal groups.
• Paleozoic rocks contain fossils of early fish and amphibians.
• During the Paleozoic, plants began to colonize the land.
• The Paleozoic ended with a mass extinction event.
• Geologists study Paleozoic deposits to understand ancient climates.
• Many coal deposits formed during the Paleozoic era.