Sue the Tyrannosaurus rex a $8.36 Million Dollar Bargain say Chicago Field Museum Officials

When Sue Hendrickson, noticed some fossilised bones eroding out of a butte in South Dakota in August 1990, she had no idea that her discovery would lead to the excavation of the most complete Tyrannosaurus rex fossil known to date.

The Tyrannosaurus rex specimen known as Sue, (after Sue Hendrickson) was sold at auction by Sotheby’s for the still world record amount for a fossil of $8.36 million USD and she made her debut as an exhibit at the Chicago Field Museum on May 17th 2000AD.

Sue the T. rex

Every day ever since; the museum has been packed with visitors eager to see the largest and most spectacular of T. rex fossils.  Although there are a number of replicas on display, the “real deal” at the Chicago museum still continues to be a major tourist attraction and officials at the museum are keen to celebrate her 10th birthday on display.

A number of events are planned at the museum to acknowledge the tenth anniversary of her being unveiled to world.  Although she was purchased for a whopping $8.3 million dollars, museum administrators and officials believe that she was a bargain.

A T. rex Fossil Specimen on Display

A Tyrannosaurus rex skeleton on display.

Picture credit: Everything Dinosaur

As well as proving to be a major tourist attraction for the Field Museum and the Chicago area in general, this particular fossil has provided scientists with an unprecedented amount of data on the physiology and the lives of large Theropods.  For example, ontogenic analysis and bone studies indicate that Sue was approximately 28 years of age when she died.  A “robust” T. rex she is believed to be a female and scientific study has shown how closely related Tyrannosauridae dinosaurs were to modern birds.  Interestingly, ontogenic (growth studies) have shown that large meat-eaters like T. rex grew throughout their lives, the rate of growth did alter, but even as a mature and relatively old (for a T. rex) age, she was still capable of growing by approximately 2 kilogrammes per day.

Back in the Maastrichtian faunal stage of the Cretaceous, a visit to what was to become South Dakota, would have been a foolish undertaking, with 40 feet long predators on the prowl.  The T. rex known as Sue was probably one of the largest in the area and a formidable predator.

The high price paid for her at auction, also changed the landscape for dinosaur hunting, not always in positive ways.  The controversy over her discovery and ownership fed an emotional debate that preceded the passage of legislation to protect fossils on public lands, legislation signed into law by President Obama.

T. rex Skeleton

Looking back, Field Museum President John McCarter said he thought that the 1997 purchase, using funds from museum patrons and corporate donors, was a good gamble merely to raise the Field’s profile a bit.  But the commotion of winning the bid, by far the most ever paid for a dinosaur, raised instant excitement about the fossil that has never really died down.

He went onto comment:

“The thing that we didn’t understand at the time was the iconic nature of Sue.  We didn’t understand the worldwide impact.”

Since Sue went on display on the 17th May, ten years ago, an estimated 16 million people have come to see her.  An estimated 6.5 million have paid to see two replicas of the fossilised skeleton in temporary exhibits and many more have seen a third replica on display at Disney World’s (Florida) Animal Kingdom.

For palaeontologists, Sue has proved to be a treasure trove of new information and discoveries. Most dinosaur species are known from just a few recovered fossil bones of any one individual animal.  With Sue, 73 percent of her approximately 300 bones were recovered, and the missing ones mostly were small ones from her ribs, tail and left foot.  Although, members of the public in our surveys always state that T. rex is the most famous of all dinosaurs, very few articulated and even associated specimens have ever been found.  Only six other discoveries to date yielded more than 40 percent of the entire skeleton.  Most importantly of all, the skull material with Sue, although a little compressed is exquisitely preserved.

Commentating on her importance to palaeontology the Field Museums Geology Collections Manager Bill Simpson stated:

“She is the Rosetta Stone for anybody who wants to study Tyrannosaurus rex and other large Theropods.  It is the completeness of her skeleton that really makes her shine in the world of palaeontology.”

The earliest studies on Sue revealed, among other things, that her large olfactory bulbs meant she had a very keen sense of smell, and the architecture of her feet suggested T. rex was not the speedy hunter some originally thought.  Estimates from work published by Manchester University don’t make T. rex a slow coach either, this research work based on computer modelling estimated an adult T. rex could run at approximately 18 miles per hour (about as fast as a professional soccer player).

To read more about the work on T.rex locomotion: So Tyrannosaurus rex could run down David Beckham.

In the last ten years, a steady stream of scientists have trooped to the Field to study her, and the Field’s chief dinosaur expert, Peter Makovicky, has enlisted collaborators from all over the world.

He added:

“We are beginning to get a better understanding of the biophysics of an animal this big.  She represents a biological extreme that exists in no other period in Earth’s history.”

The research on Sue continues, for example, a Chicago police forensics team have been training their laser scanner on her skeleton, making a 3-D computer model of it like they make of crime and accident scenes.  The model, which revised Sue’s length down from 42 to 40.5 feet, is now with a biophysicist in England who is using it to create a more accurate estimate of Sue’s body mass, her centre of mass, how much muscle was in her legs and how fast she could run and shift directions.

Papo of France have made a number of Tyrannosaurus rex models and a replica of another tyrannosaur. To view this range: Papo Dinosaur and Prehistoric Animal Models.

With such a complete specimen, one that has been so beautifully preserved and carefully prepared, there are still many new discoveries waiting for us in Sue’s 66 million year old bones.