Most celebrities hit the Las Vegas circuit a few years past their prime. For "Samson," the journey took a bit longer. The remains of the 66- million-year-old female Tyrannosaurus rex, along with 50 other lots of fossils and dinosaur parts, are being auctioned off on October 3 by Bonhams & Butterfields  New York  at The Venetian resort in Las Vegas.

Comprising 170 bones, more than half of the total bone count of an entire T. rex skeleton, the 12.2-meter- long Samson is the world's third- most complete skeleton for this species and is expected to sell for millions of dollars. (The completest T. rex skeleton is a dino named "Sue," who features 219 bones—73 percent of the total.) Samson was excavated in 1992, five years after the prehistoric predator was first discovered on a ranch near Buffalo, S.D.

Of particular interest is evidence of a healed injury on Samson's skull, near her left eye, that captures "a moment of the life of that animal in a time capsule of regenerated bone awaiting interpretation," Peter Larson, president and founder of the Black Hills Institute of Geological Research, Inc., in Hill City, S.D., said in a statement. "Life is not easy for those who make their living killing other creatures. The long extinct Tyrannosaurus rex was no exception."

Although she probably would not have appreciated it while she was alive, Samson will share the Venetian's stage with a number of other extinct specimens. This includes the world's largest set of shark jaws, featuring about 180 fossil teeth from the massive Carcharocles megalodon (estimated to fetch at least $900,000), and an 8.5-meter- long, fully mounted Edmontosaurus annectens duck--billed dino skeleton that the auction house expects will sell for at least  $375,000.

Slide Show: Prehistoric Players on the Vegas Strip