Paléogéographie des algues calcaires marines carbonifères
Three marine algal microfloral realms are recognized in the Carboniferous: (i) a Tethyan flora with numerous Dasycladales and high endemism, (ii) a North American flora with some Dasycladales and fairly low endemism, and (iii) an Arctic flora composed of Dasycladales in low numbers and with cosmopolitan assemblages. These three phytochores are interconnected by a high number of "cosmopolitan" genera and species. However "transatlantic" exchanges are limited. The floras of the American exotic terranes (Peratrovich type) have some tethyan affinities but are basically cosmopolitan.