Cancel that dating idea, as exposure dating techniques relate to exposure to atmosphere, light and cosmic rays. Obviously that doesn't work.
However there was a barnacle found between the remains, which lead to the only scientific publication about the Mega site:
First Record of the Barnacle Crustacean Genus Newmaniverruca.
Obviously this is a shallow water species and the authors could not explain how it got there at that depth of 600-700 meters. Now there is a sample to carbon date. Should not be surprized if that would be a five digit figure. Could that barnacle have lived there under normal conditions when the site made it's way to its current depth?
But then again, could somebody have thrown it in the water?