Macrofossils: Corals Flashcards
What class are corals? And when did they split off from other animal lineages?
Cnidarians. They split before bilateralism evolved.
What does each coral polyp have?
Exoskeleton
What are the respective names for sessile and motile corals?
Polyps and medusae
What type of gut do corals have?
Blind
Why are corals mostly found in shallow water?
They form symbiotic relations with photosynthetic algae.
How do corals reproduce?
Sexually or asexually
What are the two types of extinct corals and when did they go extinct?
Rugose and tabular corals went extinct at the P-T extinction.
What is the only type of extant coral?
Scleractinia
When were tabulate corals most successful?
Ordovician and Silurian
When were rugose corals most succesful?
Devonian and Carboniferous
When did scleractinian corals evolve?
Triassic
What type of seas are corals found in?
Shallow tropical seas that are agitated, oxygenated and over 18deg. C.
Define corralum
A solitary coral individual or the whole skeleton of a colonial coral, made up from individual corallites
Define theca
Skeletal wall of the coral
Define calice
The upper part of the corallum where the polyp sits
