The discovery of this incredible dinosaur involved the FBI and resulted in a scientist being sentenced to prison | Discover Wildlife

There are few T.rex more famous than ‘Sue’, one of the largest, most extensive, and best preserved T.rex skeletons ever found. Despite her completeness and the countless contributions she’s made to science, ‘Sue’ is best known for being at the centre of what may be the fiercest controversy in palaeontological history.

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Who is ‘Sue’?

‘Sue’, or to give her less catchy, officially designated catalog name, FMNH PR 2081, is a 67-million-year-old T.rex that was discovered on August 12th, 1990.

The specimen is 90% complete by bulk and 73% complete by bone count, making it not only one of the most complete T.rex ever found, but one of the most complete dinosaurs known to science.

Despite being known as ‘Sue’, scientists don’t know whether this particular T.rex was male or female. However, they can estimate how old she was based on a close examination of her bones.

In 2020, a study found that ‘Sue’ was roughly 33-years-old at the time of her death, making her the oldest T.rex specimen ever studied.

She lived a tough life too, suffering a damaged right shoulder blade, a torn tendon in her right arm, and three broken ribs – injuries that all eventually healed, indicating ‘Sue’ was a fighter who survived several near-death incidents.

How was ‘Sue’ discovered?

In 1990, a group from the Black Hills Institute – a private corporation specialising in fossil excavation and preparation – spent a summer season digging on the Cheyenne River Indian Reservation in western South Dakota, US.

While they found several bones belonging to large, plant-eating dinosaurs known as Edmontosaurus, it wasn’t until the last day of their trip, when they were preparing to leave, that they made their biggest discovery.

According to accounts, a flat tire on the group’s truck gave one worker, Sue Hendrickson, extra time to explore some nearby cliffs. As she was walking along the base of these cliffs, she discovered small pieces of bone and noticed larger bones protruding above her head.

The president of the Black Hills Institute, Peter Larson, identified these bones as belonging to T.rex and immediately ordered extra plaster to help carefully extract the delicate bones from the cliffs.

Hendrickson, who ‘Sue’ was ultimately named after, worked with a number of others to excavate the specimen, recovering 250 of its 360 known bones. Most T.rex skeletons are missing around half their bones, making ‘Sue’ an exceptionally rare and remarkably complete find.

What happened after ‘Sue’ was unearthed?

It wasn’t long after ‘Sue’ was discovered that an argument over her ownership arose.

The Black Hills Institute obtained permission to excavate the Cheyenne River Indian Reservation from Maurice Williams, the putative land owner. They also paid him $5,000 for ‘Sue’s’ remains.

However, Williams later claimed that this fee was only for access to his land and that, as per their agreement, Larson was to remove and clean the fossil for a later sale. Since he was a member of the Sioux Nation, the Native American tribe also became involved in the dispute, claiming the bones belonged to them.

As it happened, the land where ‘Sue’ was discovered didn’t exclusively belong to Williams; instead it was held in trust by the United States Department of the Interior, meaning permission had to be sought before anything found on it could be sold. So when Williams sold ‘Sue’ to the Black Hills Institute, both parties unknowingly broke the law.

In 1992, the FBI and the South Dakota National Guard raided the Black Hills Institute to seize ‘Sue’, along with related documents and a number of other fossils believed to be involved in the dispute.

A few years later, in 1996, Larson was found guilty of minor customs violations, failing to file currency reports, and minor theft of government property involving small fossils. For these crimes, the Black Hills Institute president was sentenced to two years in federal prison.

Meanwhile, the courts decreed that Williams retained ownership of ‘Sue’, giving him free rein to do with the T.rex as he pleased.

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Who owns ‘Sue’ now?

Williams decided to auction ‘Sue’ through the famous auction house Sotheby’s on October 4th, 1997.

This decision worried a lot of palaeontologists, with many fearing ‘Sue’ would be snapped up by a private collector and removed from public view.

The private ownership of fossils is a contentious point amongst palaeontologists, as fossils that disappear behind closed doors can’t be freely studied. This means that previous studies can’t be verified by other palaeontologists, and that fossils can’t be re-examined using new, emerging technologies.

For these reasons, many leading scientific journals refuse to publish studies on privately owned specimens, even those ‘on loan’ to museums for a limited time.

Thankfully, with financial help from the California State University system, Walt Disney Parks and Resorts, and – surprisingly – McDonald’s, the Field Museum of Natural History in Chicago managed to place a winning bid of $7.6 million, ensuring ‘Sue’ didn’t fall into private hands. She’s now a permanent feature at the Field Museum and accessible to both researchers and the general public.

The final cost of ‘Sue’ reached $8.3 million, making her the most expensive fossil ever sold at the time.

Since then, two other T.rex have surpassed her record – and by some margin. In 2020, ‘Stan’ was sold to Abu Dhabi’s Natural History Museum for $31.8 million, and in 2026, ‘Gus’ went under the hammer for an eye-watering $50.1 million. The owner of ‘Gus’ hasn’t yet been disclosed.

Why is ‘Sue’ considered so special?

She may be best known for the legal storm she kicked up following her discovery, but ‘Sue’ has provided palaeontologists with a treasure trove of information about T.rex.

As one of the most complete T.rex ever found, ‘Sue’ has revealed aspects of T.rex (and wider theropod) anatomy that weren’t known prior. These discoveries have allowed researchers to create biomechanical models of her arms and neck, as well as study how large theropods grew as they aged.

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‘Sue’ is also one of only a handful of nearly complete T.rex specimens not hidden behind closed doors. The fact she’s on permanent public display means that we can rely on her to continue providing palaeontologists with valuable data for decades to come.

And it’s not just palaeontologists that benefit from this – anyone can visit the Field Museum and look at ‘Sue’ in all her 12.8m-long, 3.96m tall, 14,000kg glory. She stands in the museum’s upper level in a dedicated, 5,100-square-foot suite, ready to inspire the next generation of dinosaur enthusiasts.

Top image: Tyrannosaurus Rex Sue Skeleton, 3D rendering. Credit: Racksuz/Getty Images