Sue (dinosaur)

"Sue" is the nickname given to FMNH PR 2081, which is the largest, most complete and best preserved Tyrannosaurus rex specimen ever found. It was discovered in the summer of 1990 by paleontologist Sue Hendrickson, and was named after her. It is not known if the dinosaur was male or female. The fossil was sold for the highest amount of money ever paid for a dinosaur specimen, and 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 a 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. She returned to camp with two small pieces of the bones and reported the discovery to the president of the Black Hills Institute, Peter Larson. He determined that the bones were from a T. rex by their distinctive contour and texture. Later, closer examination of the site showed many visible bones above the ground and some articulated vertebrae. The crew ordered extra plaster and, although some of the crew had to depart, Susan and a few other workers began to uncover the bones. The group was excited, as it was evident that much of the dinosaur had been preserved. Previously discovered T. rex skeletons were usually missing over half of their bones. It was later ascertained that Sue was a record 80 percent complete. 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 the skull, and the leg bones were intertwined with the ribs. The large size and the excellent condition of the bones were also surprising. The skull was nearly five feet long, and most of the teeth were still intact. After the group 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.

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, Maurice Williams, to excavate and remove the skeleton, and had, according to Larson, paid Williams $5,000 for the remains. But Williams later claimed that the money had not been for the sale of the fossil and that he had only allowed Larson to remove and clean the fossil for a later sale. Williams, 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 U.S. 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 Maurice Williams retained ownership, and the remains were returned in 1995. Williams then decided to sell the remains, and contracted with Sotheby's to auction the property. Many were then worried that the fossil would end up in a private collection where people would not be able to observe it. 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 difficulty 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. Two new research laboratories funded by McDonalds were created and staffed by Field Museum preparators whose job it was to slowly and carefully remove all the rock, or "matrix" from the bones. One preparation lab was at Field Museum itself, the other was at the newly opened Animal Kingdom in Disney World in Orlando. Millions of visitors observed the preparation of Sue's bones through glass windows in both labs. Footage of the work was also put on the museum’s website. Several of the fossil’s bones had never been discovered, so preparators 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 plastic. The preparators also poured molds of each bone. All the molds were sent to a company outside Toronto to be cast in hollow plastic. Field Museum kept one set of disarticulated casts in its research collection. The other sets were incorporated into mounted cast skeletons. One set of the casts was sent to Disney's Animal Kingdom in Florida to be presented for public display. Two other mounted casts were placed into a traveling tour that was sponsored by the McDonald's Corporation.

Once the preparators finished taking the matrix off of each bone, it was sent to the museum's photographer who made high-quality photographs. From there, the museum's paleontologists began the study of the skeleton. In addition to photographing and studying each bone, the research staff also arranged for CT scanning of select bones. The skull was too large to fit into a medical CT scanner, so Boeing’s Rocketdyne laboratory in California agreed to let the museum use their CT scanner that was normally used to inspect space shuttle parts.

Bone damage
Close examination of the bones revealed that Sue was 28 years old when it died and as such, is the oldest T. rex known. During its life this carnivore received several injuries and suffered from numerous pathologies. An injury to the right shoulder region of Sue resulted in a damaged shoulder blade, a torn tendon in the right arm, and three broken ribs. All this damage was subsequently healed (though one rib healed into two separate pieces), indicating Sue survived the incident. The left fibula is twice the diameter of the right one, likely a result of infection. Original reports of this bone being broken were contradicted by the CT scans which showed no fracture. Multiple holes to the front of the skull were originally thought to be bite marks by some, but subsequent study found these to be areas of infection instead. Damage to the back end of the skull was interpreted early on to represent a fatal bite wound. Subsequent study by Field Museum paleontologists found no bite marks. The distortion and breakage seen in some of the bones in the back of the skull was likely caused by post-mortem trampling. Some of the tail vertebra are fused in a pattern typical of arthritis due to injury. In addition, there is extra bone in some of the tail vertebrae likely caused by the stresses brought on by Sue's great size. Sue did not die as a result of any of these injuries, her cause of death is not known.

Display
After the bones were prepared, photographed and studied, they were sent to New Jersey where work began on making the mount. This work consists of bending steel to support each bone safely and to display the entire skeleton articulated as it was in life. The real skull was not incorporated into the mount as subsequent study would be difficult with the head 13 feet off the ground. Parts of the skull had been crushed and broken, and thus appeared distorted. The museum made a cast of the skull, and altered this cast to remove the distortions, thus approximating what the original undistorted skull may have looked like. The cast skull was also lighter, making it possible to be displayed on the mount without the use of a steel upright under the head. The original skull is exhibited in a case that can be opened to allow researchers access for study. When the whole skeleton was assembled, it was forty 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. Paleoartist John Gurche painted a mural of a Tyrannosaurus for the exhibit.