We are searching data for your request:
Upon completion, a link will appear to access the found materials.
On August 12, 1990, fossil hunter Susan Hendrickson discovers three huge bones jutting out of a cliff near Faith, South Dakota. They turn out to be part of the largest-ever Tyrannosaurus rex skeleton ever discovered, a 65 million-year-old specimen dubbed Sue, after its discoverer.
Amazingly, Sue’s skeleton was over 90 percent complete, and the bones were extremely well-preserved. Hendrickson’s employer, the Black Hills Institute of Geological Research, paid $5,000 to the land owner, Maurice Williams, for the right to excavate the dinosaur skeleton, which was cleaned and transported to the company headquarters in Hill City. The institute’s president, Peter Larson, announced plans to build a non-profit museum to display Sue along with other fossils of the Cretaceous period.
In 1992, a long legal battle began over Sue. The U.S. Attorney’s Office claimed Sue’s bones had been seized from federal land and were therefore government property. It was eventually found that Williams, a part-Native American and member of the Cheyenne River Sioux tribe, had traded his land to the tribe two decades earlier to avoid paying property taxes, and thus his sale of excavation rights to Black Hills had been invalid. In October 1997, Chicago’s Field Museum purchased Sue at public auction at Sotheby’s in New York City for $8.36 million, financed in part by the McDonald’s and Disney corporations.
Sue’s skeleton went on display at the Field Museum in May 2000. The tremendous T.rex skeleton–13 feet high at the hips and 42 feet long from head to toe, with a 2,000-pound skull and 58 teeth–is displayed in a special exhibition space.
Sue’s extraordinarily well-preserved bones have allowed scientists to determine many things about the life of T.rex. They have determined that the carnivorous dinosaur had an incredible sense of smell, as the olfactory bulbs were each bigger than the cerebrum, the thinking part of the brain. In addition, Sue was the first T.rex skeleton to be discovered with a wishbone, a crucial discovery that provided support for scientists’ theory that birds are a type of living dinosaur.
READ MORE: How T. Rex Got Its Ferocious Bite
NPR Traces History of Barnum Brown’s First T. Rex Skeleton
It’s a story more than a century in the making. Barnum Brown’s extraordinary fossil-hunting career—which took him from a frontier farm to the world’s top fossil sites and to the halls of the American Museum of Natural History—included the discovery of the first complete skeleton of the Tyrannosaurus rex.
The priceless fossil—the one used to describe the carnivorous species now synonymous with “dinosaur”—was displayed in the Museum for more than 30 years beginning in 1906. Then the story took a twist, which is traced in a recent NPR piece “Bone To Pick: First T. Rex Skeleton, Complete At Last.”
When the skeleton went to Pittsburgh’s Carnegie Museum of Natural History in the 1940s, one bone stayed behind, unnoticed. Then one day, a young researcher working in the Museum’s paleontology collection discovered a fossil bone tagged with the T. rex’s catalog number.
1990: The Largest Tyrannosaurus Rex Fossil in History
The skeleton was nicknamed “Sue” after its discoverer, the paleontologist Susan “Sue” Hendrickson. In the meantime, the skeleton was sold for 7.6 million dollars, the highest price ever paid for a dinosaur skeleton.
Sue Hendrickson discovered the skeleton in South Dakota. Its great value stems from the fact that it is 80% complete. It is 12.9 meters long, and it is estimated that the Tyrannosaurus Rex to which it belonged weighed around 6.4 tons when it was alive.
Due to the nickname “Sue”, it is often referred to as a female’s skeleton, but the actual sex of the individual in question remains unknown. “She” lived around 67 million years ago, and died at the age of 28.
Today the skeleton is an exhibit in the famous Field Museum of Natural History in Chicago. The skeleton’s teeth are up to 30.5 centimeters long, and its huge skull weighs 272 kilograms.
SUE the T. rex
Get to know the dinosaur known as Specimen FMNH PR 2081.
You may know SUE as the hilarious, pun-loving dinosaur turning Twitter into a personal smorgasbord. Or you might treasure that selfie you snapped with this fearsome fossil looming overhead. But there’s a lot more to SUE’s story than 280 characters or a passing glance might offer.
This specimen has been invaluable to the paleontological community since its discovery. And before settling into the luxurious life of a well-kept Chicago museum attraction, SUE had quite the history!
Dating back to the Cretaceous period—about 67 million years ago—this massive predator lived to the upper end of the life expectancy of a T. rex, about 28 years. (How do we know? Dinosaur bones have growth rings, just like trees. After examining these rings, scientists also determined that SUE had an adolescent growth spurt—gaining as much as 4.5 pounds per day—and reached full size at age 19.)
SUE’s sex is unknown this T. rex is named for Sue Hendrickson, who discovered the dinosaur in 1990 during a commercial excavation trip north of Faith, South Dakota.
Hendrickson spotted a few large vertebrae jutting out of an eroded bluff and followed her hunch that there were more beneath the surface. In the end, it took six people 17 days to extract the dinosaur’s bones from the ground where SUE was discovered.
Susan Hendrickson stands near her discovery.
© The Black Hills Institute, courtesy of Peter Larson
After excavating the fossilized bones, collectors wrapped the bones in protective plaster field jackets to remove them from the site.
© The Black Hills Institute, courtesy of Peter Larson
How did SUE get to the Field Museum?
Shortly after Hendrickson’s landmark discovery, three parties embarked on a five-year custody battle that ended in a public auction in 1997. The highest bidder? The Field Museum (with support from McDonald’s Corporation, the Walt Disney World Resort, and private donors), at a staggering $8.4 million—the most money ever paid for a fossil at auction.
SUE finally made a dramatic debut in Stanley Field Hall on May 17, 2000, but there was a lot of work to be done to get the skeleton there. After SUE was purchased at auction, 12 museum preparators spent more than 30,000 hours preparing the skeleton (plus another 20,000 hours building the exhibit).
Why is SUE so important?
At more than 40 feet long and 13 feet tall at the hip, SUE is physically the largest Tyrannosaurus rex specimen discovered, out of more than 30 T. rex skeletons that have been found. SUE is also the most complete—around 90 percent. We have 250 of the approximately 380 known bones in the T. rex skeleton, including the furcula (wishbone) and gastralia (a set of rib-like bones stretched across the dinosaur’s belly, believed to have helped SUE breathe).
Copies of SUE’s skeleton were created from molds made by our preparators. These casts were made for a variety of purposes. One complete skeleton is stored unassembled in our research collections for further study by visiting scientists. Others were assembled into mounted cast skeletons, which travel to museums and science centers around the world for international dinosaur lovers to marvel at.
All that expense and hard work has been well worth it: SUE is the most celebrated representative of T. rex and arguably the most famous fossil in the world. SUE has enabled scientists all over the world to do more detailed studies of the species’ evolutionary relationships, biology, growth, and behavior than ever before.
SUE lived in the Late Cretaceous period, depicted here in a painting by John Gurche.
What SUE has taught us
SUE has taught scientists about biomechanics and movement, dinosaurs’ intellect, and even how much SUE weighed, says Peter Makovicky, the Field Museum’s curator of paleontology. Other fossils discovered during the same excavation can also tell us about the environment SUE lived in, what the dinosaur ate, and more.
“All of this can tell a very powerful, very vivid story to the public that gives insight into how science is done,” Makovicky says. “There are questions about biology of dinosaurs—and Tyrannosaurus in particular—that you can only answer with SUE.”
For example: How did T. rex use their arms?
In 2016, one of SUE’s tiny forelimbs took a solo field trip to Argonne National Laboratory in Lemont, Illinois, where researchers took micro-CT scans of the arm to produce high-resolution images of its interior. Those scans allowed us to get a look at SUE’s bone structure—and study how our favorite dinosaur used its arms.
SUE’s skull alone has fascinated researchers for decades.
The skeleton’s skull is a cast, with the real one displayed in a freestanding case for easy access to visiting scientists. (It also weighs 600 pounds!) Much research has centered around telltale holes in SUE's lower jaw. Some scientists used to believe the holes were bite marks, but it's now more widely accepted that they were caused by a infection. (Dinosaurs: They’re just like us!)
“It’s fun to open the case with SUE’s skull inside and study this specimen in front of the public,” Makovicky says. “These things aren’t just out in the hall to be looked at.”
SUE’s skull is displayed separately from the rest of the skeleton, allowing scientists easier access.
World’s Largest T. Rex Skeleton Discovered – Nicknamed “Scotty”
The skeleton of a Tyrannosaurus Rex discovered in Canada has been confirmed as the largest ever discovered, according to a report by France 24. The skeleton was first uncovered in western Canada in 1991, and paleontologists have spent decades trying to painstakingly extract it and piece it together.
The colossal T. Rex was originally discovered by a high school teacher named Robert Gebhardt on a prospecting expedition in the Frenchman River Valley, in Saskatchewan Province, Canada.
‘Scotty’ the largest known T. rex specimen, exhibited in Japan. Photo by ★Kumiko★ CC BY SA 2.0
He had joined the expedition in order to learn how to find and identify fossils, but among his initial discoveries were a tooth and vertebra from what appeared to be an enormous T. Rex. The initial excavations were undertaken by a team of paleontologists led by Tim Tokaryk, who named the specimen “Scotty” as a nod to the bottle of fine Scotch whiskey consumed on the night of its discovery.
A life-size skeleton model of a Tyrannosaurus rex dinosaur stands in a new exhibit called ‘T. Rex: The Ultimate Predator’ at the American Museum of Natural History, March 4, 2019 in New York City. Photo by Drew Angerer/Getty Images
From an early stage, it was clear that Scotty was an extremely large example of T. Rex, but the team did not realize just how large until they were finally able to piece the skeleton together.
According to France 24, the decades-long process of extracting and reconstructing Scotty was extremely difficult. For 28 years, a team based at the Department of Biological Sciences at the University of Alberta has been painstakingly removing the hard sandstone in which the skeleton was embedded.
Tyrannosaurus Rex. Photo by Zissoudisctrucker CC BY SA 4.0
Scott Persons, a postdoctoral researcher in the Department of Biological Sciences at the University of Alberta and lead author of a recently published study about Scotty, told CTV News that extracting the bones was a very difficult process indeed. He compared it to chipping away at cement that was encrusting the fragile bones. In order to ensure that the skeleton was carefully preserved, each fragment of sandstone had to be delicately removed, piece-by-piece.
Once this laborious task was complete, the team was able to reconstruct and analyze the skeleton. Scotty is one of the best-preserved T. Rex specimens in existence, with over 70 percent of the skeleton unearthed. However, he is particularly special for a number of other reasons. Scotty measured a remarkable 13 meters long, and probably weighed more than 8,800kg. This makes him at least 400kg heavier than his closest rival, Sue, discovered in South Dakota in 1990.
Allosaurus was similar to Tyrannosaurus rex. Photo by ScottRobertAnselmo CC BY-SA 3.0
According to France 24, Scotty is also the oldest T. Rex ever to have been discovered and was in his early 30s at the time of his death. Prior to this discovery, the oldest known T. Rex was “Trix”, discovered in Montana in 2013, who appeared to have lived to the age of 30.
The discovery of Scotty offers a fantastic opportunity for paleontologists to develop an understanding of the physiology and life of the T. Rex. In particular, it demonstrates that there was considerable variability in size and shape within the species.
According to Channel News Asia, Persons commented, “There is considerable size variability among Tyrannosaurus’. Some individuals were lankier than others and some were more robust. Scotty exemplifies the robust.” He dubbed Scotty the “rex of rexes.”
Artists impression of T-rex in the wild, with prehistoric Horsetail carboniferous trees in the background
Scotty’s age and size are particularly remarkable, but according to Persons, he also seemed to have led a difficult life. His skeleton is marked with signs of struggle, disease, and violence, and he sustained many injuries over the years.
At some point during his life, he suffered from a jaw infection, sustained several broken ribs, and even bore the marks of a possible bite from another T. Rex on his tail.
After so many years of painstaking work, the team is finally ready to reveal Scotty to an international audience. The fully reconstructed skeleton will go on display at the Royal Saskatchewan Museum in May 2019.
Paleontologists recently discovered a handful of tyrannosaur skeletons in Utah's Grand Staircase-Escalante National Monument. These aren't T. rexes: The tyrannosaur category includes similar two-legged carnivores like Albertosaurus and Gorgosaurus as well.
A recent study about the fossil finding suggests that a pack of dinosaurs all died at the same time, perhaps while hunting together — which would mean not all tyrannosaurs were solitary predators in the way experts thought. Instead, some may have been social animals that worked together, like modern-day birds.
‘The Nation’s T. rex’: How a Montana family’s hike led to an incredible discovery
FORT PECK RESERVOIR, Mont. — A long time ago, in a part of this state that is now arid desert but was then humid swampland, an egg hatched. It was the beginning of an epoch-spanning life story that continues still, beginning a new chapter this week in the nation’s capital.
The egg is long gone. The skin and muscle of the animal that climbed out of it — 38 feet long and six tons once it grew — are history (or prehistory). But when it died on the banks of a creek after 18 good years at the top of the food chain, its bones settled into the enveloping mud. The current teased away the flesh, pushed its skull a few feet downstream, shifted a shoulder blade.
But more sediment filtered down, locking the skeleton in a geologic hug that would go unbroken — through 66 million winters, the collision of continents, the rise of mammals — until just before 9 a.m. on Labor Day in 1988, when Kathy Wankel caught a glimpse of that shoulder blade.
“It was right over there, just a bit of it sticking from the earth that caught my eye,” Wankel said 31 years later on her first return to the site that changed her family story and will now become part of her country’s story, too. The “Wankel T. rex”, one of the largest and most complete skeletons of the meat-eating dinosaur ever found, will debut June 8 as the star attraction of the newly refurbished, $110 million fossil hall at the Smithsonian National Museum of Natural History.
For all its ferocious reptile rep, scientists still debate whether the living Tyrannosaurus rex was a dominant predator or just a toothy scavenger, feasting hyena-like on the carrion of the late Cretaceous. But today, their fossilized remains reign unchallenged over paleo-pop culture, the iconic king of all the dinos portrayed in movies, played with in kids’ bedrooms and displayed in museums. The Smithsonian — which had a replica T. rex towering over visitors in its old dinosaur exhibit — has been desperate for a real one for decades. They are thrilled to get such a prime specimen as the one Kathy Wankel spotted that September morning.
“It’s the centerpiece,” said Kirk Johnson, director of the museum and a noted paleontologist (who thinks T. rex was a predator). “It’s the anchor of the whole exhibit, and it’s going to bring a lot of joy and excitement.”
This bony being is an ambassador from an Earth without humans. But it is also an individual with a personal history: a tale — and a tail — that has touched ranchers, researchers and dinosaur lovers for years.
Meet the Museum of Natural History's newest guest: a T. rex
WASHINGTON -- Positioned in mid-kill, the Tyrannosaurus rex towers over the prone body of its prey, a similarly huge triceratops.
Even in simulation millions of years later, it's a moment of unmistakable savage violence and an embodiment of the meaning of the word dinosaur: Greek for terrible lizard.
The massive skeleton is the culmination of a decadeslong quest by the National Museum of Natural History to acquire a rare and coveted T. rex skeleton. Until now, the museum, part of the Smithsonian network, got by with a replica skeleton, but Kirk Johnson, the museum's director, says that was never satisfactory.
"It's been kind of deeply embarrassing to be the national museum and NOT have a T. rex," he said.
The T. rex tableau is now the centerpiece of the museum's newest exhibition, the David H. Koch Hall of Fossils — Deep Time , which opens to the public on Saturday. For Johnson, it's almost impossible to overstate the power and appeal of these extinct giants.
"Kids love dinosaurs in an almost pathological way," he said, standing in the shadow of the extinct apex predator.
The museum just missed out on acquiring a T. rex back in 1997, when a nearly complete skeleton went up for auction. Chicago's Field Museum of Natural History finally won a massive bidding war for a staggering $7.6 million.
Over the years, the Field Museum has turned the dinosaur, named Sue after the explorer who discovered her in South Dakota, into a local icon and a cottage industry. Curators there have essentially built the skeleton her own wing, with a dedicated Sue-themed gift shop, her own Twitter handle and a multimedia presentation of her life story.
Johnson's staff is clearly looking to build a similar phenomenon here. Even though the exhibit won't open for several more days, an exclusively dinosaur-themed gift shop is already open for business.
After losing out on the Sue sweepstakes, the Natural History Museum got by for years with a replica named Stan. But a new opportunity arose in the form of a skeleton on display at the Museum of the Rockies in Bozeman, Montana. This skeleton was smaller and slightly less complete than Sue, and the museum there had chosen to display it with the bones arranged as they had been found in the ground.
The bones were owned by the Army Corps of Engineers, which owned the Montana land on which they were discovered, and in 2014, the Smithsonian negotiated a 50-year lease. After being shipped cross-country in a specially outfitted truck, the bones were shipped again to Canada, where a team of specialists assembled the bones and attached metal frames and holders throughout.
Now the fully assembled skeleton of the T. rex — which, when alive, was 38 feet long (12 meters) and at least 8,000 pounds (3,600 kilograms) — stands at the heart of the new exhibition hall, which contains dozens of other skeletons ranging from a gigantic mastodon to prehistoric mammals the size of house cats. The exhibition seeks to tell the evolutionary story of the planet and its wildlife through mass multiple extinction events and the steady march of evolution. About 10 feet (3 meters) from the T. rex tableau, a metal statue of Charles Darwin sits on a bench, looking thoughtful with a bird on his shoulder.
In modern times, movies like the "Jurassic Park" franchise have helped instill dinosaur mania in a new generation of young fans. But the movies also recast the T. rex as a sort of massive meathead — dangerous but also a bit dim and with tiny ridiculous-looking arms. Meanwhile, the smaller velociraptors were presented as the true menace: sleek, intelligent and vicious pack hunters. But the T. rex still holds sway in the public imagination as the ultimate predator.
Johnson said scientists are still learning new details even now about the lives and physiologies of dinosaurs. Researchers recently concluded that the Tyrannosaurus rex actually had a second set of ribs called gastralia underneath, giving it a bulkier barrel-chested appearance.
Johnson described the predator's physique as "more like a boxer than a basketball player."
August 12, 1990: Susan Hendrickson Discovered the Largest and Most Complete Tyrannosaurus Rex SkeletonPhoto: Mark Wilson/Newsmakers
August 12, 1990: Susan Hendrickson Discovered the Largest and Most Complete Tyrannosaurus Rex Skeleton
August 12, 1990: Susan Hendrickson Discovered the Largest and Most Complete Tyrannosaurus Rex Skeleton
On August 12, 1990, Susan Hendrickson discovered what turned out to be the largest and most complete Tyrannosaurus Rex skeleton. On display at the Field Museum in Chicago, Ill., the T-Rex is known as “Sue” in honor of the self-taught paleontologist who unearthed it.
Born in Chicago, Ill. on December 2, 1949, Hendrickson’s path to paleontology was an unconventional one. As a young girl, she was rebellious and adventurous. She convinced her parents to let her move to Fort Lauderdale, Fla. with her aunt. Once she discovered her love for swimming, Hendrickson dropped out of high school at age 17. After traveling around the country with her boyfriend, she
settled in the Florida Keys when she was hired by two professional divers who owned an aquarium fish business.
In the early 1960s, she began participating in wreck diving expeditions where she first cultivated her love for exploring. Hendrickson’s first introduction to fossils was during a dive in the Dominican Republic in the mid-1970s. She took a day trip to an amber mine in the mountains and became fascinated with fossils when a miner showed her an insect preserved in amber. By the mid-1980s, she became one of the largest amber providers to scientists, including discovering three perfect 23-million-year-old butterflies. By the late 1980s, Hendrickson had linked up with a team of paleontologists and joined them in discovering and excavating fossilized dolphins, seals, and sharks at an ancient seabed in Peru.
She followed one of the paleontologists from her Peru expedition to South Dakota. It was at that location where she made her incredible discovery of what she called “the biggest, baddest carnivorous beast that ever walked on earth.” On August 12, 1990, Hendrickson and her colleagues were on their way home from the field site when they got a flat tire. While she waited for the tire to be changed, Hendrickson took a walk along the foot of a nearby cliff. On the ground, she saw small fragments of bones and then she looked upward. That’s when she saw larger bones sticking out of the face of the cliff. Sure enough, she discovered the largest, most complete and best preserved Tyrannosaurus Rex ever found. Sixty-seven million years old, the T-Rex she discovered is 42 feet long with over 200 bones preserved.
Hendrickson’s discovery was extremely important in helping us better understand dinosaurs. Scientists were able to support the long-standing theory that modern birds evolved from, or are related to, dinosaurs. In addition, the fossil allowed them to learn that the T-Rex was a lot slower than had previously been hypothesized.
Two years after discovering Sue, Hendrickson joined a team of marine archaeologists in 1992 to take part in another series of diving expeditions. Two of her team’s most notable discoveries on this trip were the Royal Quarters of Cleopatra as well as Napoleon Bonaparte’s lost fleet from the Battle of the Nile.
In the last few years, she has been spending a lot of her time working on protecting the environment on an island in Honduras. In 2008, she published her autobiography “Hunt for the Past: My Life as an Explorer.” Although she was self-taught, Hendrickson received an Honorary PhD from University of Illinois at Chicago in 2000 and a Medal of Honor from Barnard University in 2002 for her contributions to paleontology and marine archaeology. Her advice to future explorers: “Never lose your curiosity about everything in the universe – it can take you places you never thought possible!”
My T. Rex Is Bigger Than Yours
Who has the most impressive and imposing Tyrannosaurus rex? Not the Smithsonian, on this National Fossil Day. See who does.
National Fossil Day, an annual celebration of all things fossil, has come around again. But not everyone is jubilant. As the government shutdown ticks on—with debate fossilized, you might say—a mighty Cretaceous carnivore has been left in limbo on the day it was supposed to be acclaimed. There is no joy in Washington, D.C., for mighty T. rex has struck out.
The dinosaur in question, fondly known as the Wankel rex, was due to arrive today, shipped off from the Museum of the Rockies in Bozeman, Montana, for a ceremonial greeting at the Smithsonian's National Museum of Natural History. That warm welcome is delayed until the spring.
Even amid the other victims of the federal shutdown, the Wankel rex truly deserved fanfare. The skeleton is one of the most important Tyrannosaurus rex fossils ever found.
To date, fossil hunters have excavated roughly 50 T. rex skeletons, ones anywhere from 5 to 80 percent complete. (That's not counting all the isolated bones and teeth that have turned up.) That's actually quite impressive, making T. rex remarkably well represented by fossil standards.
But not all of these specimens are equally important. Some are literal rock stars. The Wankel rex is one of them.
Discovered in 1988 by rancher Kathy Wankel, the fossil of this imposing predator was not only large, but the skeleton also included the first complete T. rex forelimb discovered by paleontologists. Based on past finds, they had expected that T. rex had short, stocky, two-fingered arms, but the Wankel rex finally gave researchers a complete look.
Mocking the dinosaur's puny arms would have been a mistake, though. A recent study found that the Wankel rex would have weighed in the neighborhood of nine tons, making it one hefty carnivorous customer.
Some Dinosaurs Are Bigger Than Others
But which was the most impressive and important T. rex ever found? There's no shortage of candidates, and each has its own charms.
One of the first distinctive T. rex skeletons ever found is now across the Atlantic at London's Natural History Museum (NHM). Discovered in 1900 in Wyoming, and later sold to the U.K. museum during the 1960s, the partial skeleton was originally given a different name.
American Museum of Natural History (AMNH) paleontologist Henry Fairfield Osborn first called the NHM skeleton Dynamosaurus imperiosus in the same paper that he named a different skeleton Tyrannosaurus rex. When he saw his mistake and realized both skeletons were the same species, he selected T. rex as the preferred name for the animal. Where old Dynamosaurus stands in relation to other T. rex isn't totally clear. "I don't think we have an accurate length estimate, as it's pretty fragmentary," says NHM paleontologist Paul Barrett. But one of the lower jawbones of this dinosaur is on display at the museum to give visitors some idea of the animal's size.
Much better known is the skeleton that Osborn originally dubbed Tyrannosaurus rex. That skeleton was sold by the AMNH to the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania, in 1941 for the equivalent of $110,000 in today's dollars. As the representative fossil, it reigns as what Carnegie paleontologist Matthew Lamanna calls "the world's first specimen of the world's most famous dinosaur."
And the Carnegie T. rex is a big one. The complete femur of the dinosaur is about 4.2 feet long, and the latest analysis of the whole animal estimates that it was just over 39 feet long and weighed a little more than eight tons. "The holotype is estimated as a big, but not the biggest, known T. rex individual," Lamanna says. Still, the dinosaur will always hold the pride of place as the name-holder for the species.
Only One Can Claim the Crown
Of course, the NHM and Carnegie T. rex fossils were both early finds of important historical significance. They helped outline the image of what T. rex was like. But multiple specimens have been found since then, and they continue to be uncovered in the 68- to 66-million-year-old rock strata of western North America.
"While it is true that we are learning something from all the specimens," says University of Maryland tyrannosaur expert Thomas Holtz, Jr., "the most informative specimens have been Sue and Stan." Found in 1990 and 1987, respectively, these T. rex skeletons are the most complete found so far and nicely complement each other.
Sue, on display at Chicago's Field Museum, has become a fossilized atlas of T. rex anatomy by dint of being the most complete. And the virtue of Stan, kept at the commercial Black Hills Institute of Geological Research in South Dakota, is that the dinosaur "had a nicely disarticulated but complete skull, thus allowing us access to all sides of the various bones inside," Holtz says.
Who is the king of all T. rex is trickier to answer. "Sue does seem to be the largest one, or at least the largest one we can clearly determine the size for," Holtz says. This famous T. rex stretched approximately 40 feet long and is estimated to have weighed about nine and a half tons. But the largest T. rex may have been even bigger still.
Based on clues inside the microstructure of the dinosaur's bones, Holtz says, Sue was fully grown at the time of death. But individuals vary in how large they can get, and chances are that Sue represents the average full-grown T. rex rather than an extreme example. Given the way that animals vary in terms of size and growth, Holtz suggests that "it is very reasonable to suspect that there were individuals that were 10, 15, or even 20 percent larger than Sue in any T. rex population."
So, the biggest and baddest of the tyrant dinosaurs may yet be awaiting discovery by some lucky bone sharp.
How Sue the T. Rex survived
The skeleton discovered by Hendrickson was reconstructed the way it most likely died: not in an upright position but crouched. The recovered bones stretch 40 feet and the T. rex was some 14 feet when standing. The Cretaceous period spelled the end for most of the land-based dinosaurs, perhaps due to the after-effects of an asteroid striking the earth. But this impressive specimen was probably preserved because it was layered with water and mud right after its death so its natural enemies could not transport or consume the carcass.
After excavation, the legal ownership of Sue the T. rex was a subject of great debate and a couple of lawsuits. But all that is in the past. Today, Sue is on display at the Chicago’s Field Museum after being purchased at public auction for $8.36 million. But note, even though the T. rex is named Sue, her gender isn’t known. What is known is that Sue is massive.