Sue (dinosaur)

Sue, specimen ID FMNH PR2081, is the largest, most extensive and best preserved Tyrannosaurus rex skeleton ever found. It was discovered in the summer of 1990 by Sue Hendrickson, a paleontologist, and was named after her. It is not known if the dinosaur was male or female. The fossil is now a permanent feature at the Field Museum of Natural History in Chicago, Illinois.

Discovery
During the summer of 1990, a group of workers from the Black Hills Institute, located in Hill City, searched for fossils at the Cheyenne River Indian Reservation, in western South Dakota near the city of Faith. By the end of the summer, the group had discovered Edmontosaurus bones and was ready to leave. However, before the group could depart, on August 12, a tire on their truck was deflated. While the rest of the group went into town to repair the truck, Sue Hendrickson decided to explore the nearby cliffs that the group had left unchecked. As she was walking along the base of the cliff, she discovered some small pieces of bone. She looked above her to see where the bones had originated, and observed larger bones protruding from the wall of the cliff. Although some of the crew had to depart, Susan and a few other workers began to work at uncovering the bones. The group was excited, as they found nearly all of the dinosaur's bones. Previously discovered T. rex skeletons that were usually missing more than half of their bones. Scientists believe that this specimen was covered by water and mud soon after its death which prevented other animals from carrying away the bones. Additionally, the rushing water mixed the skeleton together. When the fossil was found, the hip bones were above of the skull, and the leg bones were intertwined with the ribs. The large size and the excellent condition of the bones was also surprising. The skull was nearly five feet long, and most of the teeth were still intact. After workers completed excavating the bones, each vertebra was covered in burlap and coated in plaster, followed by a transfer to the offices of The Black Hills Institute where preparators began to clean the bones. The process required 3 to 5 months.

Dispute and auction
Soon after the remains were found, a dispute arose over who was the legal owner of the bones. The Black Hills Institute had obtained permission from the owner of the land to excavate and remove the skeleton, and had paid the landowner $5,000 for the remains. The landowner, however, was a member of the Sioux tribe, and the tribe claimed the bones belonged to them. However, the property that the fossil had been found within was held in trust by the United States Department of the Interior. Thus, the land technically belonged to the government. In 1992, the FBI and the National Guard raided the site where The Black Hills Institute had been cleaning the bones and seized the fossil. The government transferred the remains to the South Dakota School of Mines and Technology, where it was stored until the legal dispute was settled. After a lengthy trial, the court decided that the landowner retained ownership, and the remains were returned in 1995. The owner then decided to sell the remains, and contracted with Sotheby's to auction the property. When scientists learned that the remains were being prepared for auction, many were afraid that the fossil would be relocated into a private collection where the bones would not be able to be studied. The Field Museum in Chicago was also concerned about this possibility, and decided to attempt to purchase Sue. However, the organization realized that they might have had difficult securing funding and decided to request that companies and private citizens provide financial support. The California State University system, Walt Disney Parks and Resorts, McDonald's, Ronald McDonald House Charities, and individual donors agreed to assist in purchasing Sue for The Field Museum. On October 4, 1997, the auction began at $500,000; less than ten minutes later, The Field Museum had purchased the remains with the highest bid of $8,362,500. The winning bid was $7.6 million before Sotheby's commission.

Preparation and display
The Field Museum hired a specialized moving company, with experience in transporting delicate items, to move the bones to Chicago. The truck arrived at the museum in October 1997. A new research laboratory was created by the museum in order to provide preservationist the ability clean the bones. Museum visitors were provided the opportunity to observe the preservation efforts through glass windows. Some of the bones had never been found, so the preservation and display preparation personnel produced models of the missing bones from plastic to complete the exhibit. The modeled bones were colored in a reddish hue so that visitors could observe which bones were real and which bones were modern estimations. The preservationist also created several copies of each bone. One set of the casts was sent to Disney's Animal Kingdom in Florida to be presented for public display. Two other copies were placed into a traveling tour that was sponsored by the McDonald's Corporation.

As preparators cleaned and prepared the bones, the museum's research paleontologists began to study the fossilised remains. In addition to measuring and photographing each bone, the group also CT scanned select specimens. Close examination of the bones revealed that the dinosaur was of a uniquely old age at the time of death, and that a few of its ribs had been broken and subsequently healed, in addition to exhibiting signs of infection or disease.

After the bones were completely cleaned and repaired, work began on configuring the entire skeleton as a display. A steel frame was built to hold the bones in position, but the skull was too heavy to support with ease. Additionally, parts of the skull had been crushed and broken, and thus appeared distorted. The museum casted a mold of the skull, and altered the result to how approximate how the original may have appeared. The cast was also lighter, and proved easier to place onto the display. The original skull was stored in a case that museum visitors are able to observe closely. When the whole skeleton was assembled, it was forty-one feet long from nose to tail, and twelve feet tall at the hips.

The Sue exhibit opened on May 17, 2000, with more than 10,000 visitors.