Kentrosaurus
Often thought to be a "primitive" member of the Stegosauria , several recent cladistic analyses find it as more derived than many other stegosaurs , and a close relative of "Stegosaurus" from the North American Morrison Formation within the Stegosauridae . 
<triplet> Stegosaurus <subj> Stegosauridae <obj> parent taxon <triplet> Stegosauridae <subj> Stegosauria <obj> parent taxon