Tuatara
The Tuatara is a reptile of the family Sphenodontidae, endemic to New Zealand. The two species of tuatara are the only surviving members of the Sphenodontians who flourished around 200 million years ago. The tuataras resemble lizards, but are equally related to lizards and snakes, which are their closest living relatives. For this reason, Tuataras have been referred to as living fossils. This means that they have remained mostly unchanged throughout their entire history, which is approximately 200 million years.
Adult tuataras are terrestrial and nocturnal reptiles, though they will often bask in the sun to warm their bodies. Hatchlings hide under logs and stones and are diurnal, likely because adults are cannibalistic. Tuataras survive in temperatures much lower than those tolerated by most reptiles and hibernate during winter.
Tuataras probably have the slowest growth rates of any reptile, continuing to grow larger for the first 35 years of their lives. The average life span is about 60 years, however, they can live to be over 100 years old.
