1. 
   acritarch
   (from the article `Cambrian Period`) ...(0.8 inch) in diameter and were probably more than 1 metre (3.3 feet) in height. Such large size is attained by modern green algae only in warm, ... Acritarchs are a catchall group of various small microfossils that may represent the pelagically dispersed spor...
   Found op http://www.britannica.com/eb/a-z/a/13
   
   
2. 
   Acritarch
   Acritarchs are small organic fossils, present from approximately {Ma|3200} to the present. Their diversity reflects major ecological events such as the appearance of predation and the Cambrian explosion. ==Definition== In general, any small, non-acid soluble (i.e. non-carbonate, non-siliceous) orga...
   Found op http://en.wikipedia.org/wiki/Acritarch
   
   

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