On August 12, 1990, fossil hunter Susan Hendrickson discovered three huge bones jutting out of a cliff near Faith, S.D. After further uncovering the bones, the discovery turned out to be part of the largest-ever Tyrannosaurus rex skeleton ever discovered. Called Sue, after its discoverer, the 65 million-year-old specimen was over 90 percent complete. Sue is now on display at the Field Museum in Chicago.