Scientists have accidentally killed what is reportedly the world's oldest living creature.

The creature known as Ming the Mollusc, named after the Chinese dynasty, has been proven to be older than thought. Research has found that the ocean quahog (a type of clam) was 507 years old, 100 years older than previously thought.

"Preliminary analysis of the longest-lived clam by academics found it to be between 405 and 410 years. Recent further study of this clam, however, has revealed that it is 507 years old," notes Bangor University's School of Ocean Sciences.

In 2006, Ming the Mollusc was dredged alive by researchers from the bottom of the North Atlantic (near Iceland's coastline) as part of a project that was researching on climate change in the past 1,000 years.

The British researchers put Ming the Mollusc in a freezer, not aware of its age. When the quahog was taken to the lab for further study, scientists from Bangor University concluded it was 400 years old.

The creature's life came to an end when the researchers, who were not aware of its age, opened its shell for further scrutiny. At the time, the discovery made it to The Guinness Book of World Records.

"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 Dr Paul Butler, from the University's School of Ocean Sciences.

The right age implies that the clam quahog was born in 1499, which is a few years after Columbus visited America for the first time.

So how can one be sure that researchers have got the age right this time round?

"The age has been confirmed with a variety of methods, including geochemical methods such as the carbon-14 method. So I am very confident that they have now determined the right age. If there is any error, it can only be one or two years," says marine biologist Rob Witbaard of the Royal Netherlands Institute for Sea Research.

Scientists count lines in a shell to determine the age, similar to rings in tree trunks. The growth rings of quahogs can be seen on the outside of the shell and at the hinge where the two halves meet. Per scientists, the hinge is usually the best place to count the rings.

Originally, when researchers dated Ming, they counted the rings near the hinges. However, because the shell was so old many lines had become compressed. Upon looking at the outside of the shell, more rings were found from years ago.