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PALAEONTOLOGY OF THE EARLY CAMBRIAN EMU BAY LAGERSTÄTTE, KANGAROO ISLAND, SOUTH AUSTRALIA

CHRISTOPHER NEDIN

Department of Geology and Geophysics, University of Adelaide, South Australia 5005

Nedin, C. 1995. Palaeontology of the Early Cambrian Emu Bay Shale Lagerstätte, Kangaroo Island, South Australia. Palaeontological Association Annual Conference, Galway, Ireland, December 1995, Programme and Abstracts, p. 20.

ABSTRACT

The Emu Bay Shale fossil Lagerstätte at the Big Gully on the north coast of Kangaroo Island, correlates with the Tsanglanpuian of China (Botomian of Siberia) using contemporary faunas, and is thus slightly younger than the more famous Changjiang Lagerstätte from Yunnan, China. Common elements of the fauna are the trilobites Redlichia takooensis and Hsuaspis bilobata, the most common forms; the phyllocarids phyllocarids Isoxys communis, rare specimens of which have eyes preserved, and Tuzoia australis and the enigmatic form Myoscolex ateles. The rest of the fauna is comprised of the much rarer Naraoia, Anomalocaris briggsi, Anomalocarissp.,Xandarellasp. and the presumed worm Palaeoscolex antiquus. No sessile forms have been found.

The fauna is characterised, in some cases by large size, but overall by an unusual preservational style, namely red-stained calcium carbonate. The exception is form Myoscolex which is composed of phosphatised muscle blocks, which is the earliest example of phosphatised muscle tissue in the fossil record yet identified. The appendages of form Myoscolex, only rarely preserved, suggest an affinity with the middle cambrian from Opabinia rather than with the Annelida as previously suggested. The Emu Bay Shale assemblage confirms the cosmopolitan nature and diversity of Lower-Middle Cambrian forms.