Maximo, The Largest Dinosaur Ever Uncovered, Moving Into Field Museum

CHICAGO (CBS) -- The Field Museum is getting a huge new house guest, who will be moving into SUE the T-Rex's old room.

Wednesday morning, crews began installing the new titanosaur skeleton cast of "Maximo," the largest dinosaur ever unearthed.

The two-story tall Patagotitan mayorum was uncovered in Argentina in 2014. The 70-ton skeleton cast being installed at the Field Museum is the result of a $16.5 million gift from billionaire Ken Griffin, to help the Field Museum celebrate its 125th anniversary.

Crews used forklifts and pallet jacks to unload parts of the skeleton cast earlier this week. Wednesday morning used a crane to lift a 15-foot vertebrae piece to the front door. From there, they rolled it inside.

The piece weighs 2,000 pounds, and was too big for the museum's freight elevator.

Crane operator Dan O'Gean was responsible for swinging the massive bone from the sidewalk to the south entrance at the top of the stairs. He said only one thing was going through his mind as he lifted the bone.

"Just to keep it under control, and pay attention to who is signaling me and telling me what to do," he said.

Field Museum exhibitions production director Dan Breems coordinated the move.

"Using a crane to get stuff up that entrance, we do it maybe every two-three years," he said.

Crews will begin building Maximo from the feet up. He'll be ready for visitors on June 1, and museum guests will be able to stand under and touch the massive skeleton cast.

The two Dans didn't break a sweat or a bone. The 15-foot cast touched down safely on the museum's front steps in less than four minutes.

"We've brought up a viking ship, a whale skull," Breems said.

"I picked up a piece of Titanic at the Museum of Science and Industry. I've also picked up a rhinoceros," O'Gean said.

Staffers unloaded the rest of the massive skeleton from containers shipped from South America.

"It's multiple sea containers coming all the way from Argentina, through the Harbor of New York, and arriving here," said Field Museum director of exhibitions Jaap Hoogstratem.

The last part of Maximo's journey hit a snag, needing some help rolling over the rugs at the entrance, but a bit of simple elbow grease did the trick.

A 122-foot- long plant eater, Maximo was the size of two articulated CTA buses.

"It's unimaginable that this animal walked around, and found enough food to eat," Hoogstratem said.

While no more crane work will be needed to finish delivering the bones, crews said the front doors at the museum will be taken off next week to move in a set of 35-foot pterosaurs that will be part of the same exhibit.

The whole exhibit officially opens June 1, but visitors can watch Maximo grow over the next few weeks.

Maximo will stand in Stanley Field Hall, where the museum's most famous dinosaur, SUE the T-Rex, used to stand.

In addition to the skeleton cast, the display will include some real titanosaur bones, including an 8-foot thigh bone.

SUE might pale in size compared to Maximo, but she won't be forgotten. SUE is getting a new permanent exhibit – The Griffin Halls of Evolving Planet.

"There's going to be a better moment of encounter, I think, for visitors to come face-to-face with SUE, and see them in a space that they're going to be a rock star, and the star of that space," Field Museum exhibition registration assistant Lisa Geiger said.

In her new exhibit, SUE will have a new pose, and bones the public hasn't seen before. The museum will be adding her gastralia to the fossil. The bones appear to be extra ribs across SUE's belly, and weren't originally part of the display, because scientists weren't sure how to position them when the skeleton was first mounted in 2000. Since then, research has determined their function and placement.

SUE's new display will be unveiled next year.