Travels with trilobites: adventures in the paleozoic

Introduction

Cambrian period : 541-485 million years ago

Ordovician period : 485-444 million years ago

Silurian period : 444-419 million years ago

Devonian period : 419-359 million years ago

Carboniferous/permian periods : 359-252 million years ago

Trilobite thoughts and observations.