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1 Department of Geology, University of Leicester, Leicester LE1 7RH, UK
2 Department of Zoology, University of Stellenbosch, Private Bag X1, 7602, South Africa
The Upper Ordovician (Ashgill) Soom Shale lagerstätte preserves chitinozoans on the bedding planes as scattered individuals and, more significantly, in linked chains, in aggregated masses and associated with organic envelopes. Chitinozoan affinites are problematical, but the Soom Shale has a restricted biota, providing constraints on hypotheses of relationship. No graptolites or gastropods, which are possible contenders for chitinozoan production, occur. The chitinozoans are, however, associated with conodonts and orthocone cephalopods and, of all the known Soom Shale biota, these organisms present the most likely candidates for chitinozoan origination.
Key Words: Chitinozoa Ordovician South Africa affinities palynomorphs