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10 animals with the longest life spans

Jan. 19, 2010, 1:31 p.m.
Ocean quahog

Photo: Hans Hillewaert/Wiki Commons/CC License

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Ocean quahog

The ocean quahog (Arctica islandica) is a species of clam that is exploited commercially. Researchers have interpreted the dark concentric rings or bands on the shell as annual marks, much like a tree has rings. Some collected specimens have been calculated to be more than 400 years old.