Cardiodon was known only from a two unusual, heart-shaped teeth (from which it got its name), which could not be identified beyond the fact that they came from a previously unknown large reptile.
Din Cardiodon fuseseră descoperiți doar 2 dinți de inimă (de unde a primit și numele), care nu au putut fi identificați, dincolo de faptul că proveneau de la o reptilă mare, necunoscută anterior.