Kentrosaurus measured up to 17 feet long (5 m) and weighed about 2 tons, but its small brain was the size of a walnut. Its skull was long and narrow, with a toothless beak and small cheek teeth. Its head was carried close to the ground. It had hoof-like claws on its toes. Kentrosaurus had two rows of bony plates that were embedded in its back, that went from its neck to its mid-section. A double row of spikes ran from its mid-section to its tail, and a pair spikes protected its shoulders. Since these were not attached to its bones, no one is sure exactly how they were positioned. Also, the function of the plates is uncertain; perhaps they were for temperature regulation, since they contained networks of blood vessels, or maybe they were for protection or mating display purposes. The spikes were used as protection from predators. It had a very small, but long, brain. The olfactory bulbs were well developed; this is the part of the brain that gave the animal a very good sense of smell. Kentrosaurus walked slowly on four legs. Its back legs were twice as long as its front legs; this probably allowed the dinosaur to stand up briefly on its hind legs to forage for high vegetation. Kentrosaurus lived during the late Jurassic Period, about 156 to 150 million years ago. Kentrosaurus, like other Stegosaurians, may have been a herding animal. Kentrosaurus was a stegosaurian (stegosaur), whose intelligence (as measured by its relative brain to body weight, or EQ) was low among the dinosaurs. This plated dinosaur was an ate low-lying plants. It must have eaten a large amount of low-calorie plant material each day to sustain itself.
Kentrosaurus fossils have been found in Tendaguru, Tanzania, Africa. It was named in 1915 by Edwin Hennig.