Tuatara

A detailed overview of the tuatara, a unique reptile endemic to New Zealand

Tuatara

The tuatara (Sphenodon punctatus) is a reptile endemic to New Zealand, belonging to the order Rhynchocephalia. Although it resembles a lizard, the tuatara is part of a distinct lineage that dates back to the Mesozoic era. It is often referred to as a "living fossil" due to its ancient lineage and primitive characteristics.

A tuatara basking in the sun.

Taxonomy and Evolution

The tuatara is the only surviving member of the order Rhynchocephalia, which flourished around 200 million years ago. This order was once widespread, but the tuatara is now the sole survivor, making it a critical species for understanding the evolution of reptiles.

Physical Characteristics

Tuatara are medium-sized reptiles, with adults typically reaching lengths of 60 to 80 cm. They have a spiny crest along their back, which is more pronounced in males. Their skin is covered in scales, and they possess a unique "third eye" on the top of their head, known as the parietal eye. This eye is thought to be involved in regulating circadian rhythms and hormone production.

Habitat and Distribution

Tuatara are found on a number of offshore islands around New Zealand, where they inhabit forests and coastal areas. They prefer environments with ample cover and are often found in burrows, which they may share with seabirds.

Behavior

Tuatara are primarily nocturnal, although they can be seen basking during the day. They are carnivorous, feeding on insects, spiders, small lizards, and bird eggs. Tuatara have a slow metabolism and can live for over 100 years, with some individuals reaching 150 years of age.

Reproduction

Tuatara have a slow reproductive cycle, with females laying eggs only once every 2 to 5 years. The eggs are laid in shallow burrows and take 12 to 15 months to hatch, one of the longest incubation periods of any reptile. Temperature during incubation determines the sex of the offspring, a phenomenon known as temperature-dependent sex determination.

A juvenile tuatara.

Conservation

The tuatara is classified as a species of "Least Concern" by the International Union for Conservation of Nature (IUCN), but it faces threats from habitat destruction and introduced predators such as rats and cats. Conservation efforts include habitat restoration and predator control on islands where tuatara populations exist.

Cultural Significance

The tuatara holds cultural significance for the M_ori people of New Zealand, who regard it as a taonga, or treasure. It is often associated with the god T_ne Mahuta, the god of forests and birds.

Related pages

• Reptile
• New Zealand
• M_ori culture
• Conservation biology