Tuataras are large reptiles that look like big lizards and live on a few remote islands off New Zealand. They are the last remaining survivors of the great reptile radiation known as the rynchocephalians, a sister group to both the crocodilia and the snakes and lizards. They are remarkable for many reasons, but the highlight for me is their ‘third eye’, covered by skin, but located in the centre of their forehead. This, parietal eye, is the most developed third eye of any tetrapod and is equipped with a lens and retina. Although it is covered by skin it is visible in young animals. Sadly, they cannot form images as there are no accommodation muscles so this extra eye is probably only involved in photoperiodic responses, but it is still a remarkable feature. I sometimes wonder whether there are a few freak tuataras out there with a more developed one.
While they live in burrows, either on their own or shared with sea birds, it is said that you can sing to them to get them to come out. Apparently they prefer groups to soloists! A number of tuataras are kept at Chester Zoo.
Despite such a limited distribution. there are two species of Tuataras within the genus Sphenodon: S. punctatus and S. guntheri.
The three-eyed Tuatara.
Why tuatara9? Someone beat me to tuatara.co.uk...