Illustration of a Kentosaurus dinosaur. Kentrosaurus was an ankylosaurid - the same group to which its more famous cousin stegosaurus belongs. Kentrosaurus was smaller, however, at 5 meters long, 2 meters tall, and with a weight of about a tonne. Kentrosaurus lived during the Late Jurassic Period of in what is now Tanzania (163 to 145 million years ago).