In identifying the remains as those of "Palaeoscincus", Broom initially classified "Paranthodon" as an ankylosaurian, a statement backed by the research of Coombs in the 1970s. In 1929, Nopcsa identified the taxon as a stegosaurid, with which most modern studies agree. In 1981, the genus was reviewed with modern taxonomic techniques, and found to be a valid genus of stegosaurid. A 2018 review of "Paranthodon" could only identify one distinguishing feature, and while that study still referred it to Stegosauria based on similarity and multiple phylogenetic analyses, no diagnostic features of the group could be identified in "Paranthodon".