A new cap-shaped mollusc, . Emargimantus angulatus gen. et sp. nov. is described from the Arrowie Basin of South Australia. The new species is closely comparable to mollusc species from South China and North-East Greenland previously described under the generic name . Ocruranus Liu, a genus recently reinterpreted as a multiplated, possibly polyplacophoran mollusc. . Emargimantus is interpreted as a univalved helcionelloid mollusc and differs from . Ocruranus in both morphology and function. . E. angulatus represents the first discovery of . Ocruranus-like helcionelloids in the lower Cambrian of eastern Gondwana and demonstrates that these molluscs had a global distribution during the early Cambrian.