Claim: The stegosauruses, which had a short neck, small head and low brain-to-body mass ratio, used their spiked tails as a defense against predators.
Evidence: It had a short neck and a small head, meaning it most likely ate low-lying bushes and shrubs. Stegosaurus had a relatively low brain-to-body mass ratio. Today, it is generally agreed that their spiked tails were most likely used for defense against predators, while their plates may have been used primarily for display, and secondarily for thermoregulatory functions.