Tyrannosaurus rex

Part of Hall of Saurischian Dinosaurs.

T. Rex fossil mount in the Museum's Hall of Saurischian Dinosaurs. D. Finnin/© AMNH
The 4-foot-long jaw. The 6-inch-long teeth. The tiny arms. 

Almost everything about Tyrannosaurus rex indicates the enormous power of one of the largest theropod dinosaurs that ever existed.

The first skeleton of Tyrannosaurus rex was discovered in 1902 in Hell Creek, Montana, by the Museum's famous fossil hunter Barnum Brown. Six years later, Brown discovered a nearly complete T. rex skeleton at Big Dry Creek, Montana. The rock around it was blasted away with dynamite to reveal a “magnificent specimen” with a “perfect” skull. This skeleton, AMNH 5027, is on view in the Museum's Hall of Saurischian Dinosaurs. It's also reproduced in the new exhibition T. rex: The Ultimate Predator.

The Annotated Tyrannosaurus rex

The fossil was originally arranged so that the dinosaur stood upright. Museum scientists later determined that it was more accurate to show the Tyrannosaurus rex mounted in a stalking position, with its head low, tail extended, and one foot slightly raised.

Click on the + signs below to find out more about the Museum's Tyrannosaurus rex fossil.

Archival image of T. rex mounted in standing position.

Franchise Fossil

Book cover designer Chip Kidd was inspired by the Museum’s T. rex and a book he bought featuring a Museum rendering to create the iconic image for Michael Crichton’s mega-hit Jurassic Park. Using a transparency and a rapidograph pen, Kidd reworked the rendering into the terrifying silhouette now widely recognized around the world.

Walking Wounded

Many fossilized remains of T. rex feature evidence of wounds sustained in life, and the Museum’s T. rex is no exception. It has two fused vertebrae where the neck joins the rib cage. It also has two rib-bearing vertebrae that are fused further down the spine, and there is evidence several ribs were broken and healed over.

Bone by Bone

The free-standing T. rex mount in the Hall of Saurischian Dinosaurs is about 45 percent real fossils, all of them—including the vertebrae, hips, and ribs—from a specimen found by Museum fossil hunter Barnum Brown at Big Dry Creek, Montana, in 1908. The humerus and femur are casts from the T. rex specimen Brown found in 1902.

Fancy Footwork

When the 1915 display was mounted, no fossil fragments of T. rex feet had been discovered, so the feet were hand sculpted by preparator Adam Hermann using another carnivore, Allosaurus, for reference. Eventually T. rex toes were found to be slightly thinner, but the shape and position of Hermann’s correctly three-toed feet were close enough.

Historic Hunch

The first-ever mention of T. rex came in a letter written in August 1902 by legendary fossil hunter Barnum Brown to the Museum. Brown described his discovery in Montana of a heretofore unknown “large Carnivorous Dinosaur.” The next month, he reported, “There is no question but that this is the find of the season.”

Refining Timing

When Barnum Brown’s discovery of T. rex was announced in The New York Times on December 3, 1905, the story said the animal lived 8 million years ago. Reporting on the Museum’s new mount in 1915, the Los Angeles Times told readers the animal was 3 million years old. Scientists now know that T. rex lived 69 to 66 million years ago, at the very end of the Late Cretaceous Period.

A Predator Primer

Discover one of the largest and most fearsome carnivores of all time in this media-rich feature about Tyrannosaurus rex.

Learn more »
T. rex skeleton.

Celebrate #AMNH150 #TREX


The content featured in this social media gallery cannot be used without prior consent of their copyright holders.