Distant relatives of modern lobsters, horseshoe crabs, and spiders, trilobites swam the planet’s prehistoric seas for 300 million years, from the Lower Cambrian to the end of the Permian eras—and they did so very capably. Trilobite fossils have been unearthed on every continent, with more than 20,000 species identified by science. One of the most arresting animals of our pre-dinosaur world, trilobites are also favorites among the fossil collectors of today, their crystalline eyes often the catalyst for a lifetime of paleontological devotion. And there is no collector more devoted—or more venerated—than Riccardo Levi-Setti. With , a much anticipated follow-up to his classic , Levi-Setti brings us a glorious and revealing guide to these surreal arthropods of ancient Earth. Featuring specimens from Bohemia to Newfoundland, California to the Tucson Gem and Mineral Show, and Wales to the Anti-Atlas Mountains of Morocco, Levi-Setti’s magnificent book reanimates these “butterflies of the seas” in 235 astonishing full-color photographs. All original, Levi-Setti’s images serve as the jumping-off point for tales of his global quests in search of these highly sought-after fossils; for discussions of their mineralogical origins, as revealed by their color; and for unraveling the role of the now-extinct trilobites in our planetary history. Sure to enthrall paleontologists with its scientific insights and amateur enthusiasts with its beautiful and informative images, combines the best of science, technology, aesthetics, and personal adventure. It will inspire new collectors for eras to come.