The answer is the digestive system!
the digestive system of the urchin is the largest.
An Greek astronomer could have noticed the clouds moving. They also could use the stars. They didn't have much technology to do much.
They occur years apart, and the glacier theories is from research and just a theory..but the bible account of the flood is more a story instead of research and science.
Answer:
As erosion removes the tops of mountains, the crust will rise upwards. This is an example of isostatic adjustment ( last choice).