Naked Science Forum
Life Sciences => Marine Science => Topic started by: tony6789 on 03/11/2010 18:13:34
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Ok well everyone knows about the pretty little organisms we call coral. but a question i have is, is coral a relatively new species?
Coral have a rough time with water temp. changes of about 2 degrees C. So they shouldn't have been around during the last ice age..right?
If thats true, how did coral come about or evolve from?
hmmm...
thanks!
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Actually, fossilised coral has been found in sedimentary rock dating back to the Middle Cambrian, over 510 million years ago.
Skeletal deposits at the Great Barrier Reef date back around 600,000 years.
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But it HAS to be some diffrent kind of coral than what we see on in our big swimming pool on earth right?
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Sure –several different groups of major reef-builders have come and gone, and there have been times when reefs waxed and waned.
Tabulate corals were all over the place in the Ordovician and Silurian periods, but they went extinct at the end of the Permian, during that mother of all mass extinctions around 250 million years ago.
Many rugose corals went extinct then too – these included solitary “horn corals” (you can guess why they got that name) that could grow over a metre long, and other species that built reefs.
It was probably the relatively empty ecological niche left behind by the tabulate and rugose corals after the Permian extinction that let the modern reef builders - the scleractinian corals - take over. These appeared first in the Triassic and may have evolved from rugose corals.
There’s a great book on reef evolution by Cambridge scientist Rachel Wood if you want to find out more about the comings and goings of reefs.