The Nautilitoidea is a superorder within the subclass Nautiloidea, comprising the phylogenetically related Nautilida, Oncocerida, and Tarphycerida. The superorder has its roots in the Bassleroceratidae, the ancestral family of the Tarphycerida, sometimes included in the Ellesmerocerida. The Bassleroceratidae also gave rise to the Granciloceratidae, the ancestral family of the Oncocerida, which in turn gave rise to the Nautilida, which includes the Nautilidae which includes the living Nautilus.