Carinodens measured approximately 3.5 metres in length and is one of the smallest known mosasaurs. It was closely related to Globidens, though is scantly known in comparison. The holotype specimen consists of an incomplete right dentary and most subsequently referred fossils are isolated teeth. On the basis of general mosasaur standards, the teeth of Carinodens are unusually heterodont, both in morphology and size.

Carinodens, is like its close relative Globidens, considered to have been a durophagous mosasaur. Because the anteriormost part of the dentary of Carinodens is relatively slender with small pointed tooth crowns, only the posteriormost five teeth actually functioned for crushing food.