Trenton Duerksen's eyes scoured the massive skull before him, darting left and right as he searched for his nemesis: particles of fine, sticky dust that resemble gray snow.
Perched atop a scissor lift in the dinosaur wing of the American Museum of Natural History, Duerksen was standing eye to eye with Tyrannosaurus rex. His task for the day: ridding the 39-foot-long specimen of dust and dander that accumulates on it from 5 million visitors passing through the museum every year.
Duerksen started with the head. "Top-down, that's the most important rule," he said, explaining how the approach limits airborne dust and minimizes repeat cleaning.
Armed with an ordinary household duster, a vacuum strapped to his back, and wands and brushes of various sizes and shapes, Duerksen methodically worked his way across the surface of the head, cleaning 2-inch strips at a time.
When he got to the dinosaur's jaw — believed to have given it the strongest bite of any land animal ever — he switched to what looked like a cartoonishly oversized toothbrush, moving its bristles over and between 6-inch-long, conical teeth.
"I go top to bottom, side to side, and along the gum line," Duerksen said cheerfully. No flossing needed.
Duerksen is the natural history museum's "exhibition maintenance manager," meaning that he is in charge of cleaning all the objects on display in the museum's 1 million-plus square feet of exhibition space and fixing anything that breaks.
On this particular morning this month, Duerksen was cleaning T. rex, a task he performs twice a year, usually over one or two mornings before the museum is opened to the public.
But all year long, Duerksen is sweeping, dusting and repairing things that become cracked, frayed or somehow damaged — everything from the museum's 94-foot-long fiberglass blue whale to tiny shells, sponges and butterflies. (The wildlife dioramas encased in glass are rarely opened and thus exempt from the cleaning.)
"It's fun when it's really dirty," said Duerksen, who has thick, muscular fingers and wide knuckles. "You get a lot of satisfaction from seeing the fossil all shiny again."
Duerksen, 38, is an artist by training. Before joining the natural history museum two years ago, he worked as a professional illustrator and sculptor.
"We look for somebody who has good hands, the ability to handle things firmly but carefully — somebody who has attention to detail," Dean Markosian, director of exhibitions at the museum, said.
A zest for cleaning helps.
"I love to collect dust," Duerksen said, sincerely. "I love sweeping and I love vacuuming, and this is probably the most exotic form of that."
Like many people, Duerksen developed a fascination with dinosaurs at a young age in his native Kansas and began drawing them around age 5.
"They looked like enormous monsters," Duerksen said. "The imagination required to understand them is astonishing."
But Duerksen never thought of dinosaurs as being just for kids, retaining his fascination and passion for the creatures through adulthood.
When the job opportunity came up at the natural history museum, Duerksen said, "it was kind of a no-brainer. I mean, I get to stare at the T. rex."
Duerksen received training from the museum's previous maintenance manager and conservation department, Markosian said, on which vacuum tools to use when and how to hold and use them in a way that won't damage any specimens.
"Fossils are really rocks — these are very sturdy," Markosian said, adding that some of the museum's leather and taxidermy specimens are much more delicate.
Once Duerksen had finished with T. rex's head, he moved onto the spine and ribs.
His lips pursed and brow furrowed in concentration, Duerksen leaned out over the edge of the lift, his head just inches from T. rex's rib cage. Steadily, he ran the vacuum brush down the length of each rib, then went back to dust the underside of the vertebrae.
That was all he was going to get done for the day. It was almost 10 o'clock, time to open.
"We've gotta get out before the kids come in here!" he said.
Duerksen lowered the lift and hopped out, packing away his tools and carting them away. Within half an hour, the hall swarmed with school groups and tourists, many looking up in awe at one of the largest and most powerful land predators to have ever lived.
Elizabeth Arkley Hammett, 30, was visiting from Baton Rouge, La., with her husband, mother, toddler and infant.
Robby, 3, wore a dinosaur sweater, dinosaur socks and what looked like a dinosaur hand puppet. He also owns a pair of light-up dinosaur rain boots and has dinosaur sheets on his bed. He has dinosaur pants, too, but was persuaded to leave them at home.
"He's in heaven," she said.
Hammett had been excited to show Robby a completely assembled T. rex skeleton for the first time.
"I love it because it's rooted in reality, as opposed to superheroes and fairy tales," she said.
At the museum Robby, who was running back and forth between T. rex and its companion in the Hall of Saurischian dinosaurs, the Apatosaurus, was getting acquainted with the two creatures. He pointed at the bones that once formed the beefy forelimb of an Apatosaurus, and then pointed at his own arm, and said, matter-of-factly, "arm."
Then he ran across the way. It wasn't hard to imagine Duerksen marveling at a tyrannosaur when he was a kid, too. Robby pointed up at the fossil he knew and loved best.
"See?" he said. "T. rex!"