Oikozetetes from the early Cambrian of South Australia: implications for halkieriid affinities and functional morphology

Authors

  • JOHN R. PATERSON,

  • GLENN A. BROCK,

  • CHRISTIAN B. SKOVSTED


John R. Paterson [jpater20@une.edu.au], Division of Earth Sciences, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia; Glenn A. Brock [gbrock@els.mq.edu.au], Centre for Ecostratigraphy and Palaeobiology, Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia; and Christian B. Skovsted [christian.skovsted@geo.uu.se], Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden; manuscript received on 9/3/2008; manuscript accepted on 30/5/2008.

Abstract

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.

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