Sydney cockle (NSW), or ark cockle (Queensland), Anadara trapezia, is an estuarine filter-feeding bivalve. Its calcareous, heavily ribbed shell can grow to approximately 7 to 8 cm across. Its current range is along the east coast of Australia , from Queensland to Victoria. It has previously existed in Western Australia, South Australia, and the coast of New Zealand during the Middle Holocene. It has been used as a bioindicator/indicator species to study levels of the metals selenium, copper and cadmium.
- Murray-Wallace, C.V., Beu, A.G., Kendrick, G.W., Brown, L.J., Belperio A.P. and Sherwood, J.E. (2000) Palaeoclimatic implications of the occurrence of the arcoid bivalve 'Anadara trapezia' (Deshayes) in the Quaternary of Australasia. Quaternary Science Reviews 19 559-590
- Jolley, D. F., Maher, W. A. and Kyd, J. (2004) Selenium accumulation in the cockle 'Anadara trapezia'. Environmental Pollution 132:2 203-212