Sue may be the the biggest T. rex skeleton ever found, but plopped down at one end of the vast Stanley Field Hall, beneath a 70-foot-high ceiling, she looks kind of puny — “just sort of a pretty face.”

Bill Simpson, the man who uttered those words on Monday, should know. He routinely flosses Sue’s foot-long teeth and the rest of her colossal cocoa-colored bones with a giant pink feather duster.

On Monday, workers armed with allen wrenches carefully began pulling apart Sue’s mammoth claw-tipped feet in preparation for her long-awaited move to a gallery on the second floor of the Field Museum. Beginning in the spring 2019 — if all goes to plan — Sue will reappear in a space that puts her terrifying splendor into tighter focus.

Garth Dallman (left) and Bill Kochie, of Research Casting International, start with the feet to begin the monthlong de-installation. | Ashlee Rezin/Sun-Times

“A lot of people, including Steven Spielberg, comment on how small she looks, and Sue is the biggest T. rex known,” said Simpson, the museum’s head of geological collections. “When we put her in her own exhibit hall, which has only 17-foot-[high] ceilings, she’ll look better — she’ll look more proportioned to the room.”

Sue is making way for a cast of a titanosaur, a plant-eating dinosaur that’s three times the length of Sue and with a neck that will stretch up to the second-floor balcony level. It’s a bit of a gamble, removing the Field’s star attraction, but one intended, in part, to freshen things up.

Sue’s slow dismantling, expected to take three to four weeks, drew dozens of camera-wielding spectators Monday, some of whom remembered when the grandest of meat-eating dinosaurs first went on display in the city in 2000. The fossils range in size from 2-inch-long tail bone sections to thigh bones measuring some 5 feet in length.

A young girl watches de-installation of Sue, the T. rex from Stanley Field Hall, on Monday Feb. 5, 2018. The T. rex is moving to a private suite in the museum’s Griffin Halls of Evolving Planet, scheduled to be available for view in spring 2019. The de-installation will make way for a cast of a titanosaur, a 122-foot-long Patagotitan mayorum from Argentina, scheduled to arrive by June 2018. | Ashlee Rezin/Sun-Times

Judy Nykiel of Oak Lawn was there with her grandson, Graham, watching as workers gently laid the claws and knuckled toe joints on a bed of white foam.

“It’s fascinating,” Nykiel said. “We watched her come in years ago and now we’re going to see her come back … upstairs. The new one should be spectacular. She’s going to have a really nice space all to herself.”

Others were less certain about the wisdom of Sue’s move.

“I’m personally really sad about Sue moving because she’s been here a long time and a T. rex should be appreciated,” said 8-year-old Ava Burns. “I just really like having Sue here. So people don’t have to walk all the way up there to see her.”

The T. rex is moving to a private suite in the museum’s Griffin Halls of Evolving Planet, scheduled to be available for view in spring 2019. | Ashlee Rezin/Sun-Times

Simpson urged Sue lovers to be patient.

“Right now, they are [saying], ‘Oh how can you move it?’ But they don’t know what I know. When they see Sue in her new exhibit hall, they’ll love it,” he said.

Given  her value and age — the Field paid about $8.4 million for the 67 million-year-old Sue at a New York auction — does Simpson have any fears that she might not survive the move intact?

“Sue was in so many pieces when it came here; most big fossils are,” he said. “We’re really, really good at gluing things together.”