1998). The most recent organism of this kind, described as Swart- 

 puntia germsi by Narbonne et al. ( 1997) from southwestern Namib- 

 ia, comes from just below the Cambrian boundary and has been 

 dated at about 543 million years. It consists of quilted, leaflike "pe- 

 taloids," each reminiscent of the Australian form Dickensonia, but 

 attached to a central stalk. Like other members of this fauna. Swart- 

 punt ia presumably absorbed nutrients directly from the water and 

 possibly made use of photosynthetic or chemosynthetic symbionts. 

 The Ediacaran community was apparently composed of sedentary 

 or very slow-moving individuals luxuriating in a tranquil "Garden 

 of Ediacara," as Mark McMenamin (1986) has termed it. However, 

 there was indications even then that this could not last. At least one 

 of the organisms, described originally from Australia as Kimberella. 

 but now well documented from White Sea sediments in Russia (Fe- 

 donkin and Waggoner, 1997). is interpreted as having molluscan 

 affinities. It is characterized by a single unmineralized shell and 

 seems to have grazed on the algal biomat that characterized the 

 shallow seafloors at that time (Seilacher, 1999). Also attached to this 

 biomat were small cone-in-cone structures, originally described by 

 Gerard Germs ( 1972) from the Nama basin as Cloudina. These have 

 been found in many parts of the world, and is regarded as a Terminal 

 Proterozoic index fossil (Grant. 1990). The cones presumably 

 housed a filter-feeding metazoan. of at least cnidarian-grade orga- 

 nization, with tentacles protruding from the top. Of particular inter- 

 est is the fact that many Cloudina fossils from China studied by 

 Bengtson and Zhao (1992). show evidence of having been bored 

 into by predators. They wrote. 



Cloudina. the earliest known animal to produce a mineralized exoskeleton. shows 

 evidence of having been attacked by shell-boring organisms. Of more than 500 

 tubes from Shaanxi Province. China. 2.7% have rounded holes 40 to 400 micro- 

 meters in diameter. The relation between the size of the holes and the width of the 

 bored tubes suggests that the attacking organism was a predator, selecting its prey 

 for size. If true, this would be the oldest case of predation in the fossil record and 

 would support the hypothesis that selection pressures from predation was a signif- 

 icant factor in the evolution of animal skeletons around the Precambrian-Cambrian 

 boundary. (Bengtson and Zhao. 1992) 



Recently. I have come across similarly bored Cloudina tubes from 

 the Nama Basin, and these will be described shortly. 



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