When the characters in Jurassic Park first see a living dinosaur, they stand breathless watching a giant Brachiosaurus munching on leaves at the very top of a tall tree. While that dramatic scene may have been the signature “moment” for this dinosaur in popular culture, Brachiosaurus has long been an object of fascination among dinosaur fans.
Fossil of the Month: Brachiosaurus
One of the largest dinosaurs to ever walk the earth, the first Brachiosaurus fossils were described in 1903 by Elmer Riggs of the The Field Museum in Chicago. Riggs’ assistant had discovered the Late Jurassic period fossils on July 4th, 1900, near Fruita, Colorado, only five or six miles from where Riggs had uncovered another sauropod, an Apatosaurus skeleton.
Riggs realized he had found something remarkable when he found that the dinosaur’s front legs were longer than its back legs. This unusual feature inspired the name that Riggs gave it, which means “arm lizard.” Brachiosaurus also had an extremely long neck, often mounted at a steep angle like the neck of a giraffe.
For over seventy years, Brachiosaurus was the undisputed “heaviest dinosaur of all time.” With the recent discoveries of some larger dinosaurs in South America, that title is no longer accurate. But Brachiosaurus was a very large sauropod dinosaur, with an adult reaching lengths estimated at 85 feet. Early estimates for the weight of these giant dinosaurs placed them squarely as the heaviest dinosaurs, but since then, estimates have varied widely. Still, even the most conservative estimate suggests that an adult Brachiosaurus would have weighed at least 20 tons, with some estimates doubling that. The specimen Riggs discovered was later found to be a subadult, indicating that it likely could have grown even larger as it grew older.
Although quite rare, other Brachiosaurus fossils have turned up since Riggs named the animal, including some that were found before Riggs’ discovery but had not been described. In 1914, what was then called a species of Brachiosaurus was found in a massive fossil deposit on Tendaguru Hill in what is now Tanzania by German paleontologist Werner Janensch. This amazing dinosaur became the centerpiece of one of Europe’s great dinosaur museums, the Museum für Naturkunde in Berlin. The Brachiosaurus in Berlin was later found to belong to a new genus, and in 1988 was renamed Giraffatitan, the “giraffe giant.” In the mounts in Chicago and Berlin, the Brachiosaurus is posed with its neck almost straight up. There is some disagreement about how flexible the neck was, though, and a recent mount at the Museum of Ancient Life in Lehi, Utah, displays Brachiosaurus in a more traditional sauropod pose, with the neck more parallel to the body. While it was pretty cool to see on film, most paleontologists also believe that it is unlikely that Brachiosaurus would have been able to rear up on its hind legs to reach the very highest leaves as it did in Jurassic Park.
For decades, the Berlin specimen was the only mounted Brachiosaurus, as the Field Museum had not yet made a mount of the Riggs specimen. That finally changed in 1994 when they mounted a cast skeleton of their Brachiosaurus fossils and displayed it in the main hall. It took 90 years, but the majestic Brachiosaurus took center stage at a major museum in North America! Unfortunately, much like in the movie Jurassic Park, once the Tyrannosaurus rex arrived on the scene, the Brachiosaurus quickly lost its star turn.
In Chicago, the Field Museum moved the Brachiosaurus mount after “Sue” the famous T. rex arrived and was ready for display in the year 2000. After its brief, 6-year reign in the center hall, the Brachiosaurus mount went to the friendly skies of the United Airlines terminal at O’Hare International Airport, where it can still be seen today. Do not despair if you don’t fly United and are visiting the Field Museum: a metal cast of this beloved dinosaur still stands outside at the northwest corner of the building, facing the beautiful Chicago skyline.