An incomplete brachythoracid arthrodire skull acid-prepared from the Devonian limestones of the Broken River area of Queensland is described as Doseyosteus talenti gen. et sp. nov. It supposedly comes from strata dated by conodonts as late Early Devonian in age (Emsian stage), but shows several derived features of the skull, typical of Middle-Late Devonian brachythoracids, and not seen in any arthrodire from the Emsian limestones of the Burrinjuck area of NSW. The alignment with conodont zones of stratigraphic subdivisions of the Burrinjuck sequence is revised. Published information on the provenance and age of all previously described placoderm taxa from Broken River is reviewed and amended. The new taxon may be most closely related to Late Devonian (Frasnian) brachythoracids from Iran and the Gogo Formation of Western Australia.