Did Stegosaurus have two brains? This question comes from a very old misconception that keeps showing up in articles and books, probably because it sounds too weird to be true but makes an odd sort of sense. After all, when the fact that Stegosaurus’ roughly walnut-sized brain controlled a 4-ton body seems so absurd anyway, a second brain sounds like it would come in handy, right? The short answer to this question, though, is NO. ABSOLUTELY NOT. Stegosaurus had one brain ju