Kentrosaurus, whose name means "prickly lizard," was a stegosaur from the Late Jurassic of what is now Tanzania, about 150 million years ago. It lived alongside the giant sauropods of the Tendaguru beds and was discovered on the famous German expeditions there in the early 1900s. Roughly half the length of its famous relative Stegosaurus, Kentrosaurus reached about four to five meters long, but it carried one of the most extreme weapon arrays of any stegosaur: a double row of small plates ran along its neck and back, then gave way to long, wicked spikes — some up to a meter long — down the tail, with extra pairs jutting out from each flank. Paleontologists believe it held its spiked tail ready to swing like a medieval flail at any predator that came close. Its front legs were much shorter than its hind legs, giving it a distinctly downsloping posture, and it fed on low-growing plants near the ground. Fossil evidence shows it may have gathered in herds, and tail vertebrae found fused with predator bite marks hint that its defenses were sometimes tested.
