Currently, "Paranthodon" is classified as a stegosaur related to "Stegosaurus", "Tuojiangosaurus", and "Loricatosaurus". Initially, when Broom assigned the name "Palaeoscincus africanus" to the "Paranthodon" fossils, he classified them as an ankylosaurian. This classification was later changed by Nopcsa, who found that "Paranthodon" best resembled a stegosaurid (before the group was truly defined). Coombs (1978) did not follow Nopcsa's classification, keeping "Paranthodon" as an ankylosaurian, like Broom, although he only classified it as Ankylosauria "incertae sedis". A subsequent review by Galton and Coombs in 1981 instead confirmed Nopcsa's interpretation, redescribing "Paranthodon" as a stegosaurid from the Late Cretaceous. "Paranthodon" was distinguished from other stegosaurs by a long, wide, posterior process of the premaxilla, teeth in the maxilla with a very large cingulum, and large ridges on the tooth crowns. Not all of these features were considered valid in a 2008 review of Stegosauria, with the only autapomorphy found being the possession of a partial second bony palate on the maxilla.