The remarkable find includes the dinosaur’s vertebrae, ribs, hips, and lower jaw bones, representing about 20 per cent of the carnivorous predator.
Several dozen students, volunteers, scientists and others worked over the summer to excavate the bones at the Hell Creek Formation in Montana, a site well known for fossil discoveries.
The team later encased the massive skull in a protective plaster cast before lifting the 2,500lb load onto a flatbed lorry with the help of local Montana ranchers. The skull, which is four feet long, was unloaded at Seattle’s Burke Museum on Thursday.
The plaster-covered skull will be on display to the public starting on Saturday and lasting several weeks. Over the next year, paleontologists will painstakingly work on removing the rock around the skull.
Only 14 other nearly complete Tyrannosaurus rex skulls have been found, the museum said.
“We think the Tufts-Love Rex is going to be an iconic specimen for the Burke Museum and the state of Washington and will be a must-see for dinosaur researchers as well”, said leader of the expedition team Gregory Wilson.
The T. rex is named after two museum paleontology volunteers, Jason Love and Luke Tufts, who came across the large fossilised vertebrae sticking out of a rocky hillside last summer.
They were with a team collecting fossils as a part of the Hell Creek Project, led by Mr Wilson and started by Jack Horner and Nathan Myhrvold. Horner previously discovered the world’s first dinosaur embryos, and Myhrvold, former Microsoft chief technology officer, is a Burke Museum research associate.
The team knew the fossils belonged to a meat-eating dinosaur because of the large size and appearance of the bones, but they were not immediately sure if it was a T. rex.
They did not have a chance to excavate further until they returned to the site this summer.
Over the course of a month, Burke paleontologists and others used tools such as jackhammers, axes, and shovels to dig up the bones.
Scientists think the rest of the skull is there as well. They plan to return to the site next year to search for it and other parts of the dinosaur.
Experts estimate the dinosaur is 85 per cent the size of the largest Tyrannosaurus rex discovered, and based on the size of its skull, lived about 15 years.
Experts believe it roamed the earth in the late Cretaceous period.
Mr Horner said this discovery was “one of the most significant specimens yet found.”