A new genus of lonchidiid hybodontiform sharks from the Cretaceous of North Africa and South America

Abstract

Minute hybodont shark teeth from uppermost Albian–lower Cenomanian (mid-Cretaceous) continental deposits of Djebel Amour (Saharan Atlas, Algeria) are described. They are assigned to a new genus and species of Lonchidiidae, Lonchidionoides trifurcatum. Similar teeth recently reported from the Early Cretaceous of Brazil are here referred to as Lonchidionoides sp. The heterodont dentition of Lonchidionoides is characterized by clutching anterior teeth with a tricuspid crown and larger crushing posterior teeth with less individualized cusps. Lateral teeth show an intermediate morphology. The two occurrences of this non-marine hybodontiform genus may reflect the existence of a large ancestral distribution area that was divided during the opening of the South Atlantic, as previously suggested for several groups of cartilaginous and bony fishes.