Brachiosaurus

The Brachiosaurus is one of the most well-known long-necked dinosaurs. It is often thought of as the giraffe of all dinosaurs, with a long neck to reach high into the leaves of treetops.

These giant dinosaurs would have been tall enough to look into a window of a five-story building. That’s a huge dino!

When first discovered, they were thought to be the largest dinosaur, and they were the largest discovered to date, until later when we discovered the Patagotitan mayorum…

Brachiosaurus Basic Information

Name: Brachiosaurus
Pronunciation: BRAK-ee-oh-SAW-rus
Meaning: Arm Lizard
Time-Period: Late Jurassic 161-145 MYA
Classification:
- Kingdom: Animalia
- Phylum: Chordata
- Class: Reptilia
- Family: Brachiosauridae
- Genus: Brachiosaurus
- Species: B. altithorax
Diet: Herbivore
Fossil Locations: USA, Tanzania 1903

Where Did Brachiosaurus Live?

What we know as Brachiosaurus lived primarily in prehistoric North America, their fossils have been found in:

Colorado
Utah
Wyoming
Oklahoma

We used to think that Brachiosaurus also lived in Tanzania; however, those specimens have been determined to be a new species of Brachiosaurus called Brancai. Later, this other species would be moved to the sub-genus Giraffatitan instead.

Brachiosaurus Physical Characteristics

The massive Brachiosaurus is famous for its upward-sloping back and neck, one of the largest and tallest dinosaurs discovered. Its neck made up much of its length,

Unlike other sauropods, the Brachiosaurus had longer front legs, which meant that it was actually incapable of rearing on its hind legs.

Size (Length/Height): 82 feet (25 meters) / 50 feet (16 meters)
Notable Features: As a long-necked dinosaur, it actually has a relatively small head, and its front legs were longer than its rear legs. Thus, its body sloped upwards from its long tail at the ground to its long neck reaching high up in the air.
Weight: 51 tons
Appearance: The Brachiosaurus has a large, bulky body and walks on all fours. It had longer front legs, a long neck, and a small head.
Teeth: Brachiosaurus had 52 teeth that were like chisels. It would use them to grab onto and tug or nip off leaves. It didn’t chew its food; instead, it just swallowed it whole.
Eyesight: The Brachiosaurus had eyes on the sides of its small head, like many prey animals, to give it a wide range of vision.
Smell: It is believed that the Brachiosaurus had a very good sense of smell that allowed it to smell food and other animals better than it could even see them.
Hearing: Like many dinosaurs, Brachiosaurus would have been able to hear low sounds ranging from 100 to 1,000 Hz. This would have given it relatively better hearing than other dinosaurs.

What Did Brachiosaurus Eat?

Brachiosaurus had long necks that they used to reach up into the trees so they could eat large areas of foliage without having to move around.

It is also thought that it ate grinding stones or gastroliths to aid in digestion since it didn’t chew its food.

The Brachiosaurus would have eaten:

Leaves of ginkgo trees
Needles off conifers
Palm fronds
Other low-growing vegetation

Brachiosaurus move in herds, grazing on vegetation, high leaves, and foliage. When they’ve depleted the local food supply, herds of Brachiosaurus would migrate to regions with more food.

Additional Facts

Curiously placed nostrils: The Brachiosaurus had nostrils on the top of its head, which is thought to help give a superior sense of smell.
Jurassic Park Brachiosaurus: The artistically depicted versions of Brachiosaurus in the Jurassic Park movies were actually depictions based on the Brancai specimens found in Tanzania, which were part of a different sub-genus called Giraffatian.
Largest Mounted Dinosaur: While the Brachiosaurus isn’t the largest dinosaur to have existed, it is the largest, most complete skeleton we have access to. The first specimen found in Colorado is the largest display in the Field of Natural History Museum in Chicago.
Protected by size: Grown Brachiosaurus didn’t require much protection due to their massive size, having such tall legs that could easily crush predators underfoot. However, juvenile Brachiosaurus could be at risk from some predators until they grew large enough. But due to herd protection, they were largely safe, unless they were injured or grew ill and were left isolated.

FAQ

While Brachiosaurus and Brontosaurus sound similar, they are different dinosaurs. While they were alive at the same time and lived in the same areas, the Brachiosaurus is much larger and taller than the Brontosaurus.

The Brontosaurus also ate ground-level vegetation, rather than the high canopy vegetation that Brachiosaurus ate.

The Brachiosaurus had front legs that were much longer than its hind legs. Since front legs are often associated with being like arms, and the Brachiosaurus had such distinctive arms compared to others in its Family, it was given a fitting epithet.

These long arms and long neck gave it its signature upward sloping body posture, perfect for reaching into foliage.

The Argentinosaurus is bigger than the Brachiosaurus. At the time of discovery, the Brachiosaurus was the largest dinosaur discovered. However, later on, the Argentinosaurus was discovered, which was even bigger.

The Argentinosaurus was estimated to be around 88 tons and 114 feet (35 meters) long, compared to the 51-ton and 82 feet (25 meters) long Brachiosaurus.