In doing some research for the upcoming Save the…Turtles! I have discovered that the oldest living land animal is a Seychelles giant tortoise named Jonathan, estimated to be 190 years old and with a decent chance of making it to his second century.
My editor, naturally, wanted to know if there were any marine animals that are as old or older. Yes. Including one Quahog clam who is 500.
I cannot imagine anything more boring than being a clam for 500 years.