In 2006, Bangor University researchers caught what they thought was an ordinary clam off the coast of Iceland. Curious about its age, scientists cracked open its shell. They soon realized they’d made a big mistake — after initial dating, it turned out the mollusk was about 405 years old, making it the world’s oldest known animal.
Image © Leonardo Aguiar
Much like the way trees grow rings year after year, clams develop new layers on their shells each season. It’s difficult to count the growth rings on the outside of the shell due to the way it curves, which is why the clam had to be opened up to be dated. However, the rings on the inside of the shell are more compressed, which can lead to errors in counting.
A recent re-dating of the clam, nicknamed Ming for the Chinese dynasty during which it was born, has revealed that the original number was off by nearly 100 years. Carbon dating and other methods have also backed up the revised age, which is now estimated at about 507 years. Ironically, the more accurate read came from closely counting the rings on the outside of the shell, so it might not have been necessary to kill Ming to verify its age after all.
Paul Butler, one of the Bangor scientists who initially discovered the mollusk, was quick to point out in an interview with Science Nordic that Ming might not be as irreplaceable or unique as many people assume: “I also think it’s worth keeping in mind that we caught a total of 200 ocean quahogs on our Iceland expedition. Thousands of ocean quahogs are caught commercially every year, so it is entirely likely that some fishermen may have caught quahogs that are as old as or even older than the one we caught.”
Ming’s death may not have been in vain, however. The clam’s shell contains clues to the ocean’s temperature over the centuries, potentially allowing scientists to determine trends in the global climate over the past 5 centuries. Further research into Ming’s shell could bring scientists closer to an understanding of how ocean temperature affects the climate on land — and could even be compared to similar patterns found in the rings of 500 year-old trees.
Lead image © Gunnar Reis