Corals

• Corals first appeared In the Cambrian Period
• Corals are either solitary where one polyp lives alone or colonial where many polyps live together with their skeletons fused together
• Most corals have septa - plates that increase the strength of the calcium carbonate skeleton
• Corals contain an algae called Zooxanthellae. They have a Symbiotic relationship
• The Zooxanthellae use the corals waste and the coral uses their waste
• They feed by Paralysing them with stinging cells or food may become trapped by the polyps mucas
• Distribution


  Found around the Equator, On continental shelves, near land or as coral islands

  We assume past corals follow these same patterns
• Conditions for Growth


  High Light Levels

  Clear waters - Sunlight, free of mud and sediment that clog up the polyps

  High energy env - to circulate O2 and nutrients

  Marine Env.

  23 - 29*C
• Facies Fossils - Env. Indicators

  Coral skeletons are made of calcium carbonate so modern reefs are sites of limestone.