In 2012, a New York auction catalog boasted the unusual offering of a "superb Tyrannosaurus skeleton," and the winning bid was over $1 million. Eric Prokopi of Florida Fossils had brought this skeleton to market, a triumph in his career of hunting, preparing, and selling specimens. But as Paige Williams recounts in this 2018 New York Times Notable Book of the Year, a network of paleontologists alerted the government of Mongolia to the eye-catching lot—which they considered their property—and as an international custody battle ensued, Prokopi watched his life and livelihood unravel. Williams illuminates the history of fossil collecting, a murky, sometimes risky business where the lines can easily blur between poacher and hunter, collector and opportunist.