Chester Zoo 

Tuatara

Tuatara means "shields on back" in Maori, and the latin name, Sphenodon, refers to the wedge-like shape of its teeth which are fused to the jaw and not replaced.

Tuatara also have a specialised shearing action in which the lower tooth row bites upward between two parallel rows of upper teeth before sliding forward. Superficially Tuatara look like their relatives the lizards but they are in fact the last surviving representatives of the Rhynchocephalia (beak-heads), a distinctive group of reptiles.

During the time of the dinosaurs the beak-heads were diverse and successful with certain varieties achieving a global distribution. The modern day Tuatara, by contrast, is restricted to around 30 islands off the coast of New Zealand. Here they live in burrows and are active mainly at dawn and dusk. They feed on insects (wetas), snails, small lizards, baby tuatara, with large males seasonally eating sea bird eggs and chicks.

The climate of New Zealand is relatively cold compared to places usually inhabit by reptiles and Tuatara possess a relatively low metabolic rate. They grow very slowly reaching sexual maturity at 20>, continuing to grow until till they are 50 – 60 years of age, and are thought able to live for over 120 years. On the top of the head Tuatara possess a small ‘third eye’, that is directly connected to the brain and may be involved in regulating body temperature and seasonal rhythyms such as the onset of breeding.

There are currently only 2 surviving species of the genus Sphenodon.