Brachiosaurus

Brachiosaurus was a very tall plant-eating dinosaur that lived in prehistoric North America.

We don’t have a complete skeleton for Brachiosaurus. Most full-body reconstructions of Brachiosaurus are based on the related African dinosaur Giraffatitan.

At one time, the dinosaur now known as Giraffatitan was believed to be a species of Brachiosaurus. These days, scientists think they were two distinct species.

The first Brachiosaurus remains were found in Colorado, USA, in 1900.

They were unearthed by Elmer S Riggs, a scientist from Chicago. To begin with, Elmer thought he’d found a Brontosaurus, but soon realised this dinosaur must have been much bigger.

It wasn’t until 1903 that Elmer named his find Brachiosaurus. At the time, it was the largest dinosaur ever discovered.

Experts think Brachiosaurus fed on leaves from tall trees, such as conifers and tree ferns.

Brachiosaurus couldn’t chew, so it swallowed the vegetation whole.

It digested the tough leaves using a process called hindgut fermentation. Instead of breaking down food in its stomach, Brachiosaurus had a special area in its intestines where tiny bacteria helped break down the plant matter.

Some modern plant-eating animals, such as horses, elephants and rabbits, also use hindgut fermentation to digest their food.

While Brachiosaurus was a very large dinosaur, Argentinosaurus was even bigger.

Brachiosaurus was around 22 metres long, while Argentinosaurus could reach 35 metres in length.

At 80,000 kilogrammes, Argentinosaurus was also much heavier than Brachiosaurus, which weighed 46,900 kilogrammes.

However, some experts think the Brachiosaurus fossils were from an individual that wasn’t fully grown. Brachiosaurus might have been a bit larger than our current estimates – but it still probably didn’t reach the colossal size of Argentinosaurus.

Brachiosaurus’ front legs – its ‘arms’ – were longer than its back legs.

This gave the dinosaur a distinctive upward-tilted body posture, which – along with its long neck – made Brachiosaurus very well adapted for feeding on tall trees.

Brachiosaurus and Brontosaurus lived at the same time and in the same environment. They shared some similarities – both were very large plant eaters that walked on four legs and had long necks.

But Brachiosaurus was much taller than Brontosaurus, which ate ground-level vegetation.