National Geographic : 2000 Jun
people to learn about Sue and look down on the skeleton, where they can touch casts of the bones and actually get close to the real skull." Flynn leads me upstairs and through a maze of hallways, finally entering a fossil preparation lab on the third floor. Arranged on tables around the clean, brightly lit room are bones from Sue, each smooth and dark as richly aged hardwood. Spread across one table is the cast of Sue's skull-the one that will sit on the mounted skeleton-still in pieces and ready for gentle revisions. "What we're going to do by undistorting this cast," says Bill Simpson, the museum's chief preparator of fossil vertebrates, "is make the more distorted side of the skull a little less flat tened and crushed. We'll raise and straighten the midline of the snout, making it more sym metrical. We don't want to do too much, though, because then everything else changes. If you do too much to the palate, the orienta tion of the jaws and teeth changes." Simpson and Flynn now take me to a sealed room off the back of the lab. There, the real Sue skull sits atop a custom-built crate. Just as the skull's frontal bones have been distorted on the left side, the left postorbital, parietal, and squamosal bones-from the top of the skull behind the eye-moved out of position during burial and fossilization. "We still have the displaced bones, though," Simpson tells Flynn, grabbing the mahogany colored bones from their resting places on white foam pads nearby. Simpson fits them in place and regards the fit, which remains rough. The skull's right side is a smooth line, but the left bumps out strangely. "That's what I mean about trying to fix imperfections," Simp son says. "How much do we want it to imitate life as opposed to the way we found it?" Ultimately, it's decided the bones will be epoxied back into place, despite their imperfect shape. "I think it fits better to life this way," Flynn says. "And casting them before fitting them back into the skull allows for better scien tific study too. Those are advantages I like." Flynn and Simpson want to show me one of Sue's imperfections. Across the hall, on a table in Simpson's sprawling office, are two tail vertebrae that fused together during Sue's lifetime. The bones are a big, knobby mass of calcified clumps, not at all like the other smoothly curved tail vertebrae being mounted in Fraley's New Jersey warehouse. As we regard the freakish bones, Flynn is smiling. "I like these fused vertebrae so much,"