10 Facts About Brachiosaurus, the Giraffe-Like Dinosaur

Brachiosaurus exhibit outside showing dinosaurs walking among the trees.

London looks/Flickr/CC BY 2.0

The long-necked, long-tailed Brachiosaurus wasn't the biggest sauropod (which means giant, four-legged dinosaur) ever to walk the Earth, but it still ranks among the most popular dinosaurs in history, alongside Diplodocus and Apatosaurus. Learn more with 10 fascinating Brachiosaurus facts.

01
of 10

It Had Longer Front Than Hind Limbs

Brachiosaurus walking across an open landscape.

DariuszSankowski/Pixabay

Rather disappointingly, considering its long neck, long tail, and enormous bulk, the late Jurassic Brachiosaurus (Greek for "arm lizard") was named after a less impressive feature. Compared to its hind limbs, the relatively long length of its front limbs endowed this dinosaur with a distinctly giraffe-like posture. This was clearly a dietary adaptation, as the longer front limbs allowed Brachiosaurus to reach the high branches of trees without unduly straining its neck. There's even some speculation that this sauropod could rear up occasionally on its hind legs, like a giant grizzly bear!

02
of 10

Adults Could Live to Be 100 Years Old

Brachiosaurus skeleton towering over buildings in a city park.

AStrangerintheAlps/Wikimedia Commons/CC BY 3.0

As a general rule, the bigger and slower an animal is, the longer its life span. The enormous size of Brachiosaurus (up to 85 feet long from head to tail and 40-50 tons), combined with its presumed cold-blooded or homeothermic metabolism, means that healthy adults might have reached the century mark on a regular basis. This is very possible, as a full-grown Brachiosaurus would have been virtually immune to danger from predators, like the contemporary Allosaurus, once it aged out of its vulnerable childhood and teenage years.

03
of 10

It Was Probably a Homeotherm

Brachiosaurus and other dinosaurs in a Jurassic landcape digital rendering.

Nikon D300/MaxPixel/CC0

How did a dinosaur as big as Brachiosaurus regulate its body temperature? Paleontologists speculate that sauropods took a long time to warm up in the sun and an equally long time to dissipate this built-up heat at night. This would create a steady state of "homeothermy," a relatively constant body temperature at any given time of the day. This still-unproven theory is consistent with sauropods possessing a cold-blooded (reptilian), but not a warm-blooded (mammalian), metabolism. Contemporary meat-eating dinosaurs like Allosaurus, on the other hand, may have been genuinely warm-blooded, given their relatively active lifestyles.

04
of 10

It Was Discovered in 1900

Brachiosaurus skeletons on display at a Berlin museum.

Thomas Quine/Flickr/CC BY 2.0

In 1900, a fossil-hunting crew from Chicago's Field Museum of Natural History discovered a near-complete dinosaur skeleton missing only its skull in the Fruita region of western Colorado. The expedition chief, Elmer Riggs, named the type fossil Brachiosaurus. Ironically, this honor should have belonged to the famous American paleontologist Othniel C. Marsh, who nearly two decades before had incorrectly classified a Brachiosaurus skull as belonging to the distantly related Apatosaurus.

05
of 10

The Skull Was Easily Detached From Its Neck

Brachiosaurus skeleton on display outside in front of a Chicago museum.

James St. John/Flickr/CC BY 2.0

One of the odd things about dinosaurs like Brachiosaurus is that their tiny-brained skulls were only loosely attached to the rest of their skeletons — and thus, were easily detached (either by predators or by natural erosion) after their deaths. In fact, it was only in 1998 that paleontologists conclusively identified a skull discovered by the 19th-century paleontologist Othniel C. Marsh as belonging to Brachiosaurus, rather than the similar-looking Apatosaurus. This same loose-skull problem also bedeviled titanosaurs, the lightly armored sauropods that inhabited all the world's continents during the Cretaceous period.

06
of 10

It May Be the Same Dinosaur as Giraffatitan

Digital rendering of Giraffatitan.

Dmitry Bogdanov/Wikimedia Commons/Public Domain

The picturesquely named Giraffatitan ("giant giraffe") lived in late Jurassic northern Africa rather than North America. In all other respects, it was a dead ringer for Brachiosaurus, except for the fact that its neck was even longer. Even today, paleontologists are unsure whether Giraffatitan merits its own genus, or is best classified as a separate species of Brachiosaurus, B. brancai. The exact same situation holds with the giant "earthquake lizard" Seismosaurus and another famous genus of North American sauropod, Diplodocus.

07
of 10

It Was Once Believed to Be Semi-Aquatic

Close up of Brachiosaurus eating plants at dinosaur exhibit.

Eunostos/Wikimedia Commons/CC BY 4.0

 

A century ago, naturalists speculated that Brachiosaurus could only have supported its 50-ton weight by walking along the bottoms of lakes and rivers and thrusting its head out of the surface, like a snorkel, to eat and to breathe. Decades later, though, this theory was discredited when a detailed mechanical analysis demonstrated that the high water pressure of an undersea habitat would quickly have suffocated this giant beast. However, that hasn't kept some people from claiming that the Loch Ness Monster is really a 150-million-year-old Brachiosaurus or some other type of sauropod. To date, only one dinosaur, Spinosaurus, has been shown to be capable of swimming.

08
of 10

It Wasn't the Only Brachiosaurid Sauropod

Brachiosaurus and Diplodocus at a lake in dinosaur exhibit.

Steffen Marung/Wikimedia Commons/CC BY 2.0

Though the exact classification is still a matter of some dispute among paleontologists, generally speaking, a "brachiosaurid" sauropod is one that mimics Brachiosaurus' general body shape: long neck, long tail, and longer front than hind limbs. Some well-known brachiosaurids include Astrodon, Bothriospondylus, and Sauroposeidon. There's also some evidence pointing to an Asian brachiosaurid, the recently discovered Qiaowanlong. The other main category of sauropods is the "diplodocids," that is, dinosaurs closely related to Diplodocus.

09
of 10

It Wasn't the Only Sauropod in Late Jurassic North America

Brachiosaurus and several other dinosaurs in a Jurassic landscape drawing.

Gerhard Boeggemann/Wikimedia Commons/CC BY 2.5

You might think a dinosaur as big and imposing as Brachiosaurus would "crowd out" its niche on the floodplains of late Jurassic North America. In fact, this ecosystem was so lush that it could accommodate numerous other genera of sauropods, including Apatosaurus and Diplodocus. Most likely, these dinosaurs managed to coexist by evolving different feeding strategies. Perhaps Brachiosaurus concentrated on the high branches of trees, while Apatosaurus and Diplodocus held out their necks like the hoses of giant vacuum cleaners and feasted on low-lying shrubs and bushes.

10
of 10

It's One of the Most Popular Movie Dinosaurs

Brachiosaurus on display at Jurassic exhibit.

DinoTeam/Wikimedia Commons/CC BY 3.0

No one will ever forget that scene in the original "Jurassic Park" when Sam Neill, Laura Dern, and company feast their eyes on a herd of digitally-rendered Brachiosaurus, peacefully and majestically munching leaves in the distance. Even before Steven Spielberg's blockbuster, Brachiosaurus had been the go-to sauropod for directors trying to create a convincing Mesozoic landscape. This dinosaur still makes unexpected guest appearances elsewhere. For example, did you know that the creatures mounted by the Jawas in the enhanced "Star Wars: A New Hope" were modeled on Brachiosaurus?