Acanthopholis horridus is based on teeth, postcranial elements, armor plates, mostly fragmentary remains that may or may not pertain to a single individual/species. Assignment of Acanthopholis horridus to the Nodosauridae is based primarily on tooth structure and presence of tall conical spines and keeled plates that are or slightly convex medially. A.horridus is certainly a small nodosaurid, it may be a nomen dubium (Coombs,1971). There is a lot of referred material that does not obviously belong to this taxon.