In 2003, Paul Upchurch and John Martin, reviewing "Cetiosaurus", found that there is little evidence to assign the "C. oxoniensis" teeth to the skeleton, and the ""C. oxoniensis"" teeth differ from the "Cardiodon" teeth ("Cardiodon" teeth are convex facing the tongue); therefore, they supported "Cardiodon" being retained as its own genus. Upchurch "et al." (2004) repeated this assessment, and found that though the teeth have no known autapomorphies, they are those of a eusauropod. More recently, Royo-Torres "et al." (2006), in their description of "Turiasaurus", pointed out "Cardiodon" as a possible relative to their new, giant sauropod, placing it in the Turiasauria. Earlier, "Cardiodon" had been usually assigned to the Cetiosauridae or a Cardiodontidae of its own.