Paleozoic and Mesozoic Seas

Paleozoic and Mesozoic Seas

Earth’s oceans were full of life during the Paleozoic and Mesozoic eras. In the Paleozoic Era, 541 to 252 million years ago, the seas were home to trilobites, brachiopods, and early fish. Coral reefs began to form, and the first vertebrates with jaws appeared.

The Mesozoic Era, 252 to 66 ...

The Mesozoic Era, meaning the middle life of Earth's history, was a time when seas were filled with marine creatures like the mosasaurus, and dinosaurs roamed the land. This era is also known as the Age of Dinosaurs.

During this time, the planet experienced events called marine transgressions and regressions, which refer to the rise and fa...