When gonzo fossil hunter Barnum Brown first found a Tyrannosaurus rex skeleton in 1902, his team blasted a hill in Hell Creek, Montana. After the dynamite, they used horse-drawn earth movers to drag the layers of hard sandstone covering the bones. When amateur fossil hunter Susan Hendrickson found the biggest T. rex skeleton ever on August 12, 1990, all she needed at first were her eyes. Three gigantic bones were literally poking out from a cliff in Faith, South Dakota. The bones turned out to be part of the largest T. rex ever spotted on earth. Named “Sue” in honor of the discoverer, this dinosaur skeleton had remained mostly intact for some 65 million years, since the Cretaceous period. Hendrickson’s employer, Black Hills Institute of Geological Research, sent a team that was able to excavate and clean almost 90 percent of this massive skeleton.

How Sue the T. Rex survived

The skeleton discovered by Hendrickson was reconstructed the way it most likely died: not in an upright position but crouched. The recovered bones stretch 40 feet and the T. rex was some 14 feet when standing. The Cretaceous period spelled the end for most of the land-based dinosaurs, perhaps due to the after-effects of an asteroid striking the earth. But this impressive specimen was probably preserved because it was layered with water and mud right after its death so its natural enemies could not transport or consume the carcass.

After excavation, the legal ownership of Sue the T. rex was a subject of great debate and a couple of lawsuits. But all that is in the past. Today, Sue is on display at the Chicago‚Äôs Field Museum after being purchased at public auction for $8.36 million. But note, even though the T. rex is named Sue, her gender isn’t known. What is known is that Sue is massive.