How can you tell how old a shark is?? That question has bugged scientists for many years now and it certainly isn’t something that is easily done – it’s not as if they come with a birth certificate. In some species you can count the rings in their vertebrae, as you would the rings of a tree trunk, but this doesn’t tend to work for most species, especially those in the deep. Now an international team of scientists are using eye lenses to age Greenland sharks and, in doing so, may have just stumbled across the oldest living vertebrate on earth today. […]

via Greenland sharks may be the oldest vertebrate animal alive today — Shark Devocean