The "historical sciences"—geology, paleontology, and archaeology—have made extraordinary progress in advancing our understanding of the deep past. How has this been possible? Adrian Currie explains that these scientists are "methodological omnivores," with a variety of strategies and techniques at their disposal to uncover truths about prehistory. Covering plenty of ground, this cross-discipline survey encompasses a prehistoric duck-billed platypus, Mayan ritual sacrifice, giant Mesozoic fleas, and Mars's mysterious watery past.