Bivalved arthropods from the Lower Cambrian Mernmerna Formation, Arrowie Basin, South Australia and their implications for identification of Cambrian 'small shelly fossils'

An assemblage of bivalved arthropods from the Mernmerna Formation on 'Angorichina Station' in the Flinders Ranges, South Australia contains six bradoriid species, one phosphatocopid, and the spine of Isoxys. The assemblage includes several species that facilitate correlation with the Stansbury Basin of South Australia, but also with faunas from other Cambrian palaeocontinents, including Antarctica, China and Laurentia. One new taxon, Spinospitella coronata gen. et sp. nov. is described. This species is represented by both complete shields and numerous characteristic spines and fragments, fuelling a general discussion on the possible identification of bradoriid remains among the numerous problematic 'small shelly fossils' of the Lower and Middle Cambrian.