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A menagerie of trilobitesClick to Enlarge ImageIf you had been able to scuba dive during the Ordovician Period, some 450 million years ago, you would have seen at once that the seas swarmed with trilobites. These distant relatives of scorpions and spiders cruised the primeval oceans for nearly 270 million years before extinction finally took the life of the last trilobite about 250 million years ago. Despite their ancient departure, the trilobites left behind a rich fossil record in many parts of the world. Paleontologist Richard Fortey reconstructs the diverse habits practiced by the trilobites, which contributed to their evolutionary success.

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