CHITINOZOAN CHAINS AND COCOONS FROM THE UPPER ORDOVICIAN SOOM SHALE LAGERSTATTE, SOUTH-AFRICA - IMPLICATIONS FOR AFFINITY

The Upper Ordovician (Ashgill) Soom Shale lagerstatte preserves chitin ozoans on the bedding planes as scattered individuals and, more signif icantly, in linked chains, in aggregated masses and associated with or ganic envelopes. Chitinozoan affinites are problematical; but the Soom Shale has a restricted biota providing constraints on hypotheses of r elationship. No graptolites or gastropods, which are possible contende rs for chitinozoan production, occur. The chitinozoans are, however, a ssociated with conodonts and orthocone cephalopods and, of all the kno wn Soom Shale biota, these organisms present the most likely candidate s for chitinozoan origination.