Stegosaurus

Part of Hall of Ornithischian Dinosaurs.

A mounted stegosurus fossil shown next to a small model of the dinosaur.

At one time, some scientists thought Stegosaurus had a second brain because the one in its head seemed so small. Stegosaurus did, however, manage with one small brain.

Stegosaurus plates have grooves for blood vessels, indicating that they were covered with skin when the animal was alive. These plates were probably used in display or species recognition, much like the horns of many modern animals, including deer and antelope.