Article: Upper Cambrian (Idamean) trilobites from western Queensland, Australia

This paper reviews new and hitherto poorly understood trilobites from the type section of the early upper Cambrian Idamean Stage on Glenormiston Station, western Queensland. Revisions of local species of Pseudagnostus, Proceratopyge, Eugonocare, Stigmatoa, and Pagodia (Idamea) are given. Two new genera, Aplotaspis (Ceratopygidae) and Prismenaspis (Elviniidae) are established as well as the new species Pseudagnostus curtare, P. margopronus, Proceratopyge cryptica, Aplotaspis mucrora, Aphelaspis australis, Eugonocare whitehousei, E. quadrata, Prismenaspis brownensis, and P. aha. Representatives of Pterocephalia, Yuepingia, and Prochuangia are recorded from Australia for the first time. A biostratigraphic summary for the Idamean Stage and notes of its correlation are given together with discussions of the biomere concept and the significance of the basal Idamean faunal discontinuity.