Stegosaurus

What it was like

Stegosaurus walked on four legs and carried a row of large, upright plates along its back, ending in sharp spikes near the tip of its tail. It grew up to about 9 meters (30 feet) long and could weigh around 5 metric tons.

It had a small head and short jaws, so it most likely browsed on low plants rather than reaching into trees. The tail spikes were probably used for defense, while the plates may have been for display or for controlling body temperature.

Its world

Stegosaurus lived from about 155 to 143 million years ago, spanning the Late Jurassic and Early Cretaceous, in what is now the western United States and Portugal. Its bones come from the Morrison Formation, alongside sauropods like Brachiosaurus, Brontosaurus, Diplodocus, and Apatosaurus.

Allosaurus lived in the same habitat and may have preyed on Stegosaurus, at least on younger or weaker animals.

How it was found

Marsh named Stegosaurus in 1877. Roughly 76 fossil finds of the genus have been recorded, though many early skeletons were incomplete, so it took years for paleontologists to work out the correct arrangement of its plates.