More than 3.5 billion years ago, the Earth was not the hospitable world we know today. The atmosphere lacked oxygen, the seas were acidic and rich in iron, and volcanic activity roared across a barren ...

One hypothesis suggests the fossils may have been traded for use in ritual or medicinal practices, researchers said. Photo by Jens Lehmann. During an excavation on Morocco’s Mogador Island, ...

Intro -- Table of Contents -- Preface -- Acknowledgments -- Part I. Fossils Are Where You Find Them -- 1. Fantastic Fossils -- 2. How Are Fossils Formed? -- 3. What Kinds of Rocks Yield Fossils? -- 4.