Brachiosaurus: The tallest plant-eater of Jurassic North America

Brachiosaurus is one of the tallest dinosaurs in the museum: it carried a very long neck and could reach high up to feed. Most sauropods have short front legs and long hind legs, but Brachiosaurus is the opposite — its front legs are longer, so its back rises upward like a long, gentle slope.

Its body

The extra-long front legs lifted the shoulders high. The head was small, sitting on a neck built from a series of vertebrae. Because of this shape, the head could reach about 9 to 13 metres up — roughly the height of several storeys. Its nostrils sat on a raised bump on top of its head. Early researchers guessed from this that Brachiosaurus lived underwater, breathing through the bump; modern studies have long rejected that idea. Brachiosaurus lived on land and used its long neck to reach high leaves.

An adult probably weighed between 30 and 40 tonnes. It needed several hundred kilograms of leaves each day, so it likely spent much of its day walking and eating slowly.

Where it lived and what it ate

Brachiosaurus was a plant-eater, feeding mainly on the leaves of tall conifers and ferns. It lived in the late Jurassic in North America, when the climate was warm and damp and the vegetation was rich — a good world for such a giant herbivore. Like many sauropods, it may have lived in groups.

Where its fossils were found

Its fossils come mainly from North America, especially Colorado in the United States. It is one of the most famous late Jurassic dinosaurs, and it was the very first dinosaur to appear in the film Jurassic Park.

What the fossils tell us — and what they do not

The skeleton tells us about the longer front legs, the sloping back and the great size, but the colour of the skin and how the neck was normally held have to be reconstructed. The old idea that it lived underwater was overturned as science progressed — and the same caution applies to the colours and pose you see here.

A note for grown-ups

You could compare heights with a child: Brachiosaurus could reach about 13 metres up — how many floors of your building would that be? Turning a number into something a child can imagine is both fun and memorable.