And that's the issue for Stegosaurus. According to Peter Galton, a curator at Yale's Peabody Museum, the first Stegosaurus specimen - described by Marsh in 1877 - is too incomplete to compare with other fossils, which therefore invalidates the genus name. Instead, more complete stegosaurs such as Kentrosaurus,Lexovisaurus and Tuojiangosaurus may become the new holotype.
Source: New Scientist
p.s Best thing about Stegosaurus? The spiked tail cluster revels in the name of a thagomizer. I bloody love that word. And I love the story behind it even more. Its origins lie in this Gary Larson 'Far Side' cartoon from 1982.