Shells of 'Oikozetetes' and isolated halkieriid sclerites from a section of the lower Cambrian Mernmerna Formation in the Flinders Ranges, South Australia, are tentatively considered as being derived from the same scleritome. Details of shell morphology and the possible combination of biomineralized shell and sclerites suggest that 'Oikozetetes', if interpreted correctly, is closely related to 'Halkieria'. A new interpretation of 'Oikozetetes' shell morphology, in addition to the first report of paired muscle scars on the interior surface, sheds new light on the possible functional morphology of halkieriid shells and the means of attaching the shell to the body. The occurrence of 'Oikozetetes' in South Australia extends its biostratigraphic range to the lower Cambrian and biogeographic range to East Gondwana.

An assemblage of bivalved arthropods from the Memmema 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 Basinof 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.

A diverse, well preserved fossil assemblage consisting of micro- and macro-sized molluscs, sponge spicules, chancelloriid sclerites, hyolithelminth tubes, tommotiids, protoconodonts and lobopodian sclerites from the Third Plain Creek Member (Pararaia bunyerooensis Zone) of the Mernmerna Formation in the eastern Flinders Ranges, Arrowie Basin, South Australia is described. Molluscs are represented by hyoliths, helcionellids and a single bivalve species. The enigmatic helcionellid taxon Marocella mira is formally described for the first time from the Arrowie Basin and forms the basis of a new helcionellid family, the Marocellidae. Sclerites of the lobopodian Microdictyon jinshaense Zhang and Aldridge are described for the first time outside South China. Whilst many of the taxa are biostratigraphically long ranging, several species in the assemblage facilitate correlation across the Arrowie Basin, with the neighbouring Stansbury Basin to the south, and also with faunas from other Cambrian palaeocontinents, including Antarctica, South China and Laurentia.

The tommotiid 'Camenella reticulosa' is redescribed based on new collections of well preserved sclerites from the Arrowie Basin (Flinders Ranges), South Australia, revealing new information concerning morphology and micro-structure. The acutely pyramidal mitral sclerite is described for the first time and the sellate sclerite is shown to be coiled through up to 1.5 whorls. Based on 'Camenella', a model is proposed by which tommotiid sclerites are composed of alternating dense phosphatic, and presumably originally organic-rich, laminae. 'Camenella' is morphologically most similar to 'Lapworthella', 'Kennardia', and 'Dailyatia', and these taxa are interpreted to represent a monophyletic clade, here termed the "camenellans", within the Tommotiida. Potential reconstructions of the scleritome of Camenella are discussed and although a tubular scleritome construction was recently demonstrated for the tommotiids Eccentrotheca and Paterimitra, a bilaterally symmetrical scleritome model with the sclerites arranged symmetrically on the dorsal surface of a vagrant animal can not be ruled out.

A new assemblage of early Cambrian bivalved arthropods (Bradoriida) is described from the Arrowie Syncline in the northern Flinders Ranges, South Australia. The well preserved, largely endemic fauna comprises a total of six taxa (including five new species): 'Jiucunella phaseloa' sp. nov., 'Jixinlingella daimonikoa' sp. nov., 'Mongolitubulus anthelios' sp. nov., 'Neokunmingella moroensis' sp. nov., 'Phasoia cf. spicata' (Öpik, 1968), and 'Sinskolutella cuspidata' sp. nov. This assemblage is derived from a carbonate sedimentary package representing a high energy, shallow water archaeocyath-Renalcis biohermal facies of Terreneuvian, Stage 2 age which transitions up-section to a more restricted, low energy, intra-shelf lagoonal environment that correlates with a Cambrian Series 2, Stage 3 age. The new taxon 'J. phaseloa' sp. nov., has a first appearance datum (FAD) in shallow water biohermal facies of the Hideaway Well Member of the Wilkawillina Limestone at a level 47 m below the FAD of 'Pelagiella subangulata' which is taken to approximate the base of Series 2, Stage 3 in South Australia. Along with 'Liangshanella circumbolina', this makes 'J. phaseloa' sp. nov. amongst the oldest bivalved arthropods in South Australia and potentially greater Gondwana. The presence of 25 bradoriid taxa from the early Cambrian of South Australia suggests East Gondwana represents a major centre of origin for the Bradoriida.