What's the world's oldest living animal?

There are some reports of sea anemones living for thousands of years. Coral have been known to live for a really long time, as well. However, in terms of a single creature, British researchers discovered a four-hundred-year-old quahog [kwaw-hawg] clam at the bottom of the Arctic Ocean.

They discovered it's age by counting the rings on its shell. Similar to trees, clam shells have a ring for every year the clam has lived. The quahog found had more than four-hundred rings. Though it may not be the oldest animal ever to have lived, it's the oldest mollusk scientists have found so far. Unfortunately, it died soon after the scientists dredged it up from the sea bottom.

How was it able to live so long? Well, that's the million dollar question, and there's no clear answer. Scientists think it may have to do with the animal's cell turnover rate, meaning that the clam's cells could divide much slower than other animals.

Studying these clams could potential lead to break throughs on how we age. The hope is that this clam and other long-lived animals can help us understand how to slow the damaging effects of aging and keep people strong and healthy into old age.