Ammonoids and the correlation of the Lower Carboniferous rocks of eastern Australia

The occurrence of ammonoids in the Lower Carboniferous rocks of eastern Australia is reviewed within a biostratigraphic framework provided by the brachiopod zones that have been summarized most recently by Jones & Roberts (1976). Ammonoid abundance is low at all stratigraphic levels. Nowhere are more than 20 specimens known at a locality, and usually there are only one or two. The group is too sparse to be used for local or regional correlation, and its main value is for the intercontinental correlation of a number of well separated horizons. The rocks dated range in age from middle Tournaisian (Tn_2a) to late Visean V_3c). Some relatively minor differences between ammonoid and conodont ages remain to be resolved. The biogeography is briefly discussed.

The type specimens of all available previously described species have been examined and where necessary they are re-illustrated. New species described are Irinoceras tuba, Muensteroceras jenkinsi, M. delepinei, M. merlewoodense, Beyrichoceras mackellari, B. bootibootiense, Nomismoceras pseudocyclus, Goniatites mundubberensis, G. cuniculus, Protocanites careyi, and Cantabricanites jelli. Several species that are probably new are described under open nomenclature.     

Dental disease evidence for agricultural intensification in the Nubian C-Group

The results of this study reveal significantly greater frequencies of caries, periapical abscesses and ante-mortem tooth loss in the Lower Nubian C-Group (ca. 2000–1500 BC) compared with the preceding Classic/Terminal A-Group (ca. 3100–2500 BC). More severe tooth wear in the C-Group, which traditionally would be interpreted as consistent with a hunting-gathering subsistence base, can instead be attributed to grit in the diet resulting from the processing of agricultural produce with sandstone and quartzite mortars and grinding stones, and perhaps also to the intentional addition of grit to grain in order to facilitate grinding. The results of this study, when evaluated in the context of complementary archaeological and osteological evidence, indicate that both groups practised a mixed economy but that the C-Group relied more heavily on cereal cultivation.