Tuatara (too uh TAH ruh) is the name for two species of lizardlike reptiles that live only on a few small islands off the coast of New Zealand. Tuataras are the only living members of an ancient group of reptiles that appeared on earth more than 200 million years ago.

Tuataras have scaly, gray or greenish skin. They have enlarged scales down the back and tail. Males can grow more than 2 feet (60 centimeters) long. Females are shorter. Tuataras sleep during the day, often in burrows dug by sea birds. They emerge at night to hunt insects, amphibians, snails, birds, and small lizards. They have sharp teeth with which they easily tear up prey. A tuatara's tail breaks off easily. If an enemy seizes the tail, the tuatara sheds the tail. It then grows a new tail.

After mating with a male, a female tuatara carries from 8 to 15 eggs inside her body for nearly a year. She then deposits the eggs in a burrow, where they develop for more than a year before hatching. The eggs of no other reptile take as long to develop.

Tuataras grow slowly and do not mate until they are about 20 years of age. These animals live a long time. The longest a tuatara is known to have lived is 77 years.

Tuataras make up the order Rhynchocephalia in the class Reptilia. The scientific name for the more common species is Sphenodon punctatus.