The Tuatara is the only surviving reptile of an order which flourished 200 million years ago. They are unique in many ways. They have two rows of upper teeth which overlap one row on the bottom. They are able to hear though possess no external ear and have a third eye (parietal eye) visible as a hatching, its function still the subject of research.
Tuatara reproduce very slowly taking 10 years to reach maturity and females lay eggs (with soft parchment like shells) only once every 2 to 5 years. The average life span is 60 but they can live to well over 100 years.