The Ultimate Dinosaur Wiki

Brachiosaurus, meaning 'arm lizard', was a large sauropod from the Late Jurassic period.

A Brachiosaurus, the 'arm lizard'

Fact File

Length: 25 metres

Height: 15 metres

Weight: 50 tonnes

Diet: Herbivorous

Arm Lizard

Brachiosaurus was so named due to the fact that its front legs were longer than its back legs, like a giraffe. This made it taller than most other dinosaurs. Palaentologists once thought Brachiosaurus was the biggest dinosaur ever, but now bigger dinosaurus like Argentinosaurus and Sauroposeiden have been found, so Brachiosaurus is no longer the biggest dinosaur.


Brachiosaurus fossils were first found in the Grand River Canyon, western Colorado, USA, by Elmer Riggs, in 1900. He named the specie Brachiosaurus altithorax in 1903. Much later, in 1994, the bones Elmer Riggs discovered were put on display in the Field Museum of Natural History (Chicago).


Brachiosaurus, being so large, would have had to eat for 20 hours a day. The way it found enough food was by using its long neck to stretch high into treetops, where other dinosaurs couldn't reach. This may be the whole reason Brachiosaurus was so

The massive brachi.jpg

tall. Like most Sauropods, Brachiosaurus had pencil-shaped teeth at the front of its mouth. It would rake leaves off trees and swallow them whole, and then it would swallow gastroliths to grind up the food in the stomach.

Being eaten

Brachiosaurus would have been prey to Allosaurus. When it was young, old, weak and sick it was very vulnerable. Ways of defending itself were to use its whip-like tail, or even its long neck, to swipe at the Allosaurus. Its carcasses would also be a target for scavengers, as they were so big.