Tuatara are reptiles endemic to New Zealand. Although resembling most lizards, they are part of a distinct lineage, the order Rhynchocephalia. Their name derives from the Māori language, and means "peaks on the back". The single species of tuatara is the only surviving member of its order, which flourished around 200 million years ago. Tuatara are sometimes referred to as "living fossils".The species has between five and six billion base pairs of DNA sequence, nearly twice that of humans. Hatteria is considered in danger of extinction since 1895.