Conodont data in relation to resolution of stage and zonal boundaries for the Devonian of Australia

Conodont distribution data are presented for key Early and Middle Devonian low-yield (1–2 specimens per kg), thick, shallow water carbonate sequences of eastern Australia, principally from central New South Wales and northern Queensland and particularly for the intervals late Pridoli-Pragian (eosteinhornensis to sulcatus zones) and Eifelian-early Givetian (costatus to varcus zones). Distributional data for the dehiscens-costatus interval and Late Devonian have been presented elsewhere. That there are no well documented kindlei-pirenae sequences suggests this may have been a largely erosional interval for Australia. Good sections through the Frasnian-Famennian and Devonian-Carboniferous boundaries occur in the Canning Basin of Western Australia. It is demonstrated that the conodont zonal system based on Northern Hemisphere faunas can be applied to Australian faunas with much greater confidence than was previously thought. Most of the sequences considered, especially Eifelian or older horizons, lack icriodontans and thus may be discriminated as a discrete, very shallow water conodont biofacies, here referred to as the ozarkodinan biofacies. Occasionally, because of association with dolomites and massive limestones with fenestral fabrics, this biofacies may be interpreted as verging on hypersalinity.