Selachian scales from the Cenomanian (Late Cretaceous) of Bathurst Island, northern Australia

Abstract

Seven selachian scale types are described from the middle Cenomanian Moonkinu Formation, outcropping on the southern shores of Bathurst Island in northern Australia. The scales are classified in accordance with previously published scale morphologies of Cretaceous and modern sharks, and are representative of the Orders Squatiniformes (Family Squatinidae), Carcharhiniformes (Family Scyliorhinidae), and Lamniformes (Family Odontaspididae). The presence of typically bottom-dwelling, shallow-water angelsharks (squatinids), catsharks (scyliorhinids), and sand tiger sharks (odontaspidids) within the Moonkinu Formation support an inner neritic depositional environment interpretation for the unit, previously determined from foraminiferal biofacies and lithology. The biostratigraphic potential of these scales can only be assessed after scales from more Cretaceous localities are described and documented.