The discovery that a clam called Ming reached the age of 507 has made headlines around the world. As has the news that the scientists behind the find accidentally killed the poor old (very old) bivalve in the process of trying to work out its age. It's an epic shellfish saga, with all the makings of a rather tasty story. But dig a little deeper, and there's more lurking beneath the shell of this morsel of news.(BBC News)