Histological study of the jaw teeth in the Devonian actinopterygian †Cheirolepis canadensis (Whiteaves)

†Cheirolepis bears two series of teeth on its jaws: one with sharp caniniform teeth and a second one with smaller teeth. The good preservation of the fossil material from Miguasha (Canada) has allowed a histological study of the various tissues of teeth and jaws. Caniniform teeth are composed of a core of orthodentine with an apical cap of acrodine. The walls of the pulp cavity show incipient folds located at the tooth base. These folds are considered a primitive type of plicidentine whose function was to reinforce the attachment of the teeth, given that this taxon is being considered as a predator. The jaws are composed of cellular bone that shows evidence of limited remodelling.