Transporting readers to dinosaur excavations across the globe, paleontologist Novacek (Dinosaurs of the Flaming Cliffs) offers a spellbinding natural history of our planet, as well as the equally fascinating story of how he fell into the profession. As a child, Novacek mined for bones in the backyards of Los Angeles, studied the geostrata of the Grand Canyon, discovered a trilobite fossil in a Wisconsin quarry and frequently visited the local La Brea Tar Pits. Though Novacek claims he's no Indiana Jones, he finds himself on the wrong side of a gun more than once—whether the gun be held by Mexican drunkards or the Yemeni army. The most rousing passages depict stormy expeditions to Chilean Patagonia in search of fossilized whale vertebrae along an ancient shoreline in the Andes—an incredible 10,000 feet above sea level. Novacek's team also discovered rare dinosaur trackways that today appear to scale the vertical walls of deep canyons, and the team accomplished what Charles Darwin set out to do 150 years earlier—they collected fossils of giant sloths, armadillos and the peculiar glyptodonts for the study of mammalian vertebrae. Novacek mixes heady science—his explanations of Carbon-14 dating, geological development, ancient magnetic forces and paleontological history are clear and dynamic—with hard-grit adventure, making for a passionate memoir that readers will find appealing, especially, perhaps, young "dinophiles" in search of a vocation. Illus. (Feb.)