Eukaryota; Fungi/Metazoa group; Metazoa; Eumetazoa; Bilateria; Coelomata; Deuterostomia; Chordata; Craniata; Vertebrata; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Tetrapoda; Amniota; Sauropsida; Sauria; Lepidosauria; Sphenodontia; Sphenodontidae; Sphenodon

The lizard-like tuatara grows to 70 cm in length and lives on 30 or so small islands off New Zealand. It is the only member of the order Rhynchocephalia. The other three reptile orders are Crocodilia (crocodiles, alligators, caimans and gavials), Testudines (turtles, tortoises and terrapins) and Squamata (lizards and snakes).  It has a long life-span with sexual maturity not reached for twenty or so years. On many of the islands the population consists almost wholly of old adults.