Examination of new Late Cambrian samples from the upper part of the Chatsworth Limestone and lower part of the Ninmaroo Formation from Black Mountain, Georgina Basin, western Queensland (representing the pre-Payntonian, Payntonian and Datsonian Stages) has delineated five conodont assemblages in an interval that had previously not been subdivided using conodonts. Examination of the conodont fauna unambiguously confirms that the entire Payntonian Stage is of Cambrian age, as earlier indicated by the trilobite fauna, and provides three conodont assemblages that may subsequently form the basis for a conodont zonation. The Datsonian Stage, defined by the FAD of the Cordylodus proavus conodont assemblage and previously considered to equate with the Early Tremadoc (= Early Ordovician) of Europe, is now considered to represent the terminal Cambrian stage in northern Australia. The base of the Ordovician, equated with the base of Tremadoc correlatives, lies close to the Datsonian/Warendian boundary on the Black Mountain section. Two new conodont genera, Eodentatus and Hispidodontus, are established, along with four new species, E. bicuspatus, H. resimus, H. appressus and H. discretus. All are found in the Payntonian Stage in the upper part of the Chatsworth Limestone or the lower part of the Ninmaroo Formation.