It was classified as "cf." "Mantellisaurus" by McDonald (2012), as cf. "Mantellisaurus atherfieldensis" by David Bruce Norman (2012), and made the holotype of a separate genus and species "Mantellodon carpenteri" by Gregory S. Paul (2012). The generic name combines Mantell's name with a Greek "odon", "tooth", analogous to "Iguanodon". The specific name honours Kenneth Carpenter for his work on dinosaurs in general and iguandonts in particular. David Norman, in 2013, considered Paul's description of "Mantellodon" to be inadequate, identical to that given by Paul of "Darwinsaurus" and entirely incorrect, noting that no dentary is preserved in the holotype specimen, and that the preserved forelimb elements "are gracile, carpals are not preserved, the metacarpals are elongate and slender, and a thumb spike is not preserved". Norman considered the holotype specimen of "Mantellodon carpenteri" to be referable to the species "Mantellisaurus atherfieldensis".