How to Tell Brachiosaurus and Brontosaurus Apart
Brachiosaurus means ‘arm lizard’ (named due to its unusually long limbs), which was a giant and giraffe-like dinosaur. Brachiosaurus long-neck dinosaurs were found in North America, Africa, and Tanzania in the mid to late Jurassic period, i.e. 155.7 million to 150.8 million years ago.
Brontosaurus is a large sauropod dinosaur which lived between the late Jurassic to the early Cretaceous period, i.e. 163.5 million to 100.5 million years ago. It is one of the best-known dinosaurs.
What is Brachiosaurus?
Brachiosaurus is known as one of the tallest dinosaurs on Earth that had larger front legs and shorter hind legs. These features made it easier to hold its neck up.
Brachiosaurus size was 31'-43' tall, body 59'-69' long, and 8'-11' broad, and weight was more than 50 tons. They were herbivores that depended mainly on gymnosperms such as cycads, ginkgos, and conifers.
These were used to eat up approximately 400 kg of plant dry matter every day. This giant dinosaur had a distinct large nare over its skull and also had a short tail at its back end.
Large air sacs connected to the lung system were present in the neck and trunk. These invaded the vertebrae and ribs by bone resorption and greatly reduced the overall body density.
The neck was held in a slight S-shaped curve, with the lower and upper sections of the body bent and the middle section straight.
Brachiosaurus had very elongated neck ribs that ran down the underside of the neck, overlapping various preceding vertebrae.
These bony structures were attached to neck muscles at their ends and allowed these muscles to operate in distal portions of the neck.
At the same time, these bony rods themselves were being located closer to the trunk, lightening the distal neck portions.
Brachiosaurus probably had a small shoulder hump between the third and fifth dorsal vertebra, where the sideward and upward-directed vertebral processes were longer.
The rib cage was deep compared to other sauropod dinosaurs.
What is Brontosaurus?
Brontosaurus was named ‘thunder lizard’ by Othniel Charles Marsh as he had thought that the ground must have thundered when such a huge animal walked by.
There are three species: B. excelsus, B. yahnahton, and B. parvus. The most special feature of this giant dinosaur is its long whip-like tail used as a weapon. They were herbivores and had long necks.
They had forelimbs that were shorter than their hindlimbs. Brontosaurus's height was 28 feet, length was 72 to 85 feet, and they had a weight of 30.5 tons.
They were one of the longest dinosaurs that lived on earth.
The vertebrae of the neck of Bractosaurs were deeply bifurcated, i.e. they carried spines that were paired, leading to a wide and deep neck.
The spine and tail included 15 cervicals, ten dorsals, five sacrals, and about 82 caudals.
The dorsal ribs were neither fused nor tightly attached to their vertebrae, instead being loosely articulated. Ten dorsal ribs were on either side of the body.
The large neck was filled with an immense system of weight-saving air sacs.
Similarities Between Brachiosaurus and Brontosaurus
Brontosaurus and Brachiosaurus are two giant dinosaurs, and both of them had long necks.
Both of them were herbivores.
They are sauropod dinosaurs.
The Difference Between the Brontosaurus and Brachiosaurus
Brachiosaurus is a giraffe-like dinosaur that lived in the mid to late Jurassic period on the earth.
On the other hand, Brontosaurus is an elephant-like dinosaur that was present on the earth from the late Jurassic period to the early Cretaceous period. Brachiosaurus was heavier as well as around 20 feet taller than Brontosaurus. Additionally, there was a remarkable difference in their limb sizes as well. Brachiosaurus had larger and longer forelimbs than hind limbs. While Brontosaurus had slightly shorter forelimbs than hind limbs. On top of that, Brachiosaurus had a large nare, while Brontosaurus didn’t have one.
Interesting Facts
Adults of Brontosaurus and Brachiosaurus could live up to 100 years.
Brontosaurus and Brachiosaurus are one of the most famous movie dinosaurs.
In 1989, the United States Post Office issued four new stamps that included the Brontosaurus.
Key Features of The Cambrian Explosion
Brontosaurus and Brachiosaurus are two giant dinosaurs that are found on Earth.
Brontosaurus was named ‘thunder lizard’ while Brachiosaurus is known as one of the tallest dinosaurs on Earth.
Both the Brachiosaurus and Brontosaurus were sauropods.
Brachiosaurus long-neck dinosaurs were found in the mid to late Jurassic period, i.e. 155.7 million to 150.8 million years ago.
Brontosaurus is a large sauropod dinosaur which lived between the late Jurassic to the early Cretaceous period, i.e. 163.5 million to 100.5 million years ago.
FAQs on Brachiosaurus vs Brontosaurus: Differences, Similarities & Facts
1. What is the main difference between Brachiosaurus and Brontosaurus?
The main difference lies in their body structure and posture. Brachiosaurus had front legs that were significantly longer than its hind legs, giving it a giraffe-like, upward-sloping posture. In contrast, Brontosaurus had hind legs that were longer than its front legs, resulting in a more horizontal back and a lower-slung neck posture.
2. How can you distinguish Brachiosaurus from Brontosaurus by their key features?
You can distinguish them by observing several key anatomical features:
- Posture: Brachiosaurus had a steep, inclined back with high shoulders, while Brontosaurus had a more level, horizontal back.
- Neck: While both had long necks, Brachiosaurus likely held its neck more vertically to browse from tall trees, whereas Brontosaurus likely held its neck more horizontally for low-to-mid-level browsing.
- Build: Brontosaurus was exceptionally robust and heavily built, even for a sauropod. Brachiosaurus was also massive but appeared less stocky due to its different proportions.
- Tail: Brontosaurus is known for its very long, whip-like tail, a feature it shared with others in its family like Diplodocus.
3. Why was the name Brontosaurus considered scientifically invalid for many years?
The name Brontosaurus was considered invalid due to a famous paleontological mix-up during the 'Bone Wars' of the late 19th century. After its discovery, scientists concluded in 1903 that the Brontosaurus skeleton was actually just a more mature version of a previously discovered dinosaur, Apatosaurus. According to scientific naming rules, the older name (Apatosaurus) takes precedence, so the name Brontosaurus was officially retired for over a century.
4. To which dinosaur families do Brachiosaurus and Brontosaurus belong?
They belong to different sauropod families, which explains their distinct body plans. Brachiosaurus is the most famous member of the family Brachiosauridae, characterised by their long front legs. Brontosaurus belongs to the family Diplodocidae, which also includes Apatosaurus and Diplodocus, known for their massive size and long, whip-like tails.
5. How did the different body structures of Brachiosaurus and Brontosaurus influence their feeding habits?
Their different body structures suggest they occupied different ecological niches. Brachiosaurus's giraffe-like build, with its high shoulders and upward-reaching neck, made it a natural high-browser, allowing it to feed on leaves and branches from the tops of tall conifers. Conversely, Brontosaurus's more horizontal posture made it a low-to-mid-level browser. It likely used its long neck to sweep across large areas of vegetation like ferns and cycads without having to move its massive body.
6. If Brontosaurus was once classified as Apatosaurus, what evidence led to it being recognised as a separate genus again?
In 2015, an extensive study using advanced computer analysis re-evaluated the relationship. Researchers examined hundreds of subtle anatomical features across dozens of skeletons from the Diplodocidae family. They found that the differences between the original Apatosaurus fossils and the fossils once named Brontosaurus were numerous and consistent enough to justify separating them. This led to the scientific reinstatement of Brontosaurus as a valid and distinct genus.
7. How does Brontosaurus compare in size to its relatives, Apatosaurus and Diplodocus?
While all were massive, they had different builds. Brontosaurus was one of the heaviest and most robustly built of the three. Apatosaurus was very similar in size and build, though some studies suggest it was slightly more massive. Diplodocus, while famous for being one of the longest dinosaurs ever, was actually more slender and lightweight than both Brontosaurus and Apatosaurus.
8. During which geological period did Brachiosaurus and Brontosaurus live?
Both Brachiosaurus and Brontosaurus lived during the Late Jurassic Period, approximately 155 to 150 million years ago. Their fossils are most famously found in the Morrison Formation in North America, indicating they were contemporaries in the same ecosystem.
