The mollusc, named Ming, was calculated to be 405-years-old when scientists accidentally killed it by opening its shell. New calculations have now emerged that the original age of the quahog clam was actually 507-years-old when it died - a good 102 years older than estimated.
It means Ming, named after the Chinese dynasty, was born in 1499. Ming was found alive by climate change experts from Bangor University in north Wales on a trip dredging the seabeds of Iceland in 2006, 'Daily Mirror' reported.
After the discovery, scientists counted the rings on the inside shell to work out Ming's age. "We got it wrong the first time and maybe we were a bit hasty publishing our findings back then.
But we are absolutely certain that we've got the right age now," said Ocean scientist Paul Butler from Bangor University.
"The nice thing about these shells is that they have distinct annual growth lines, so we can accurately date the shell material.
"That's just the same as what archaeologists do when they use tree rings in dead wood to work out the dates of old buildings," Butler said.
The quahog only grows in summer when the water is warm and it feasts on plankton, each year growing a layer as thin as 0.1 millimetres.