The archaic reptile can live for over a century, survive refrigeration and is equipped with a third eye. So please don’t confuse it with a lizard.
The ancient, enigmatic tuatara, shrouded in darkness. Picture taken at the Kiwi Birdlife Park in Queenstown, New Zealand.
Tuataras are not lizards. In fact, they are the last survivors of a completely different order of reptiles that stretches back some 240 million years to when the dinosaurs were emerging. Tuataras, as the last members of the Rhynchocephalia Order, are incredibly ancient — the very definition of a living fossil. Every animal closely related to them is entombed in stone.
The Rhynchocephalia reptiles experienced their heyday some 200 million years ago. They were essentially the ecological precursors to lizards, occupying many roles that lizards have now. After their 140 million year run, most of them bowed out, along with the dinosaurs, at the end of the Cretaceous Period. All except for the tuataras, which have carried the Rhynchocephalia torch for the last 60 million years. They are the ultimate survivors.
Two species of tuatara are left today, Sphenodon punctatus and the rare Sphenodon guntheri. The word tuatara is Maori for ‘spikes’ or ‘peaks’ thanks to the spines that run along its back. On the surface, tuataras are somewhat mundane in appearance, resembling a medium-sized, brownish-green lizard that reaches between 12 and 30 inches long, making them New Zealand’s largest reptiles. But look a little closer and its prehistoric roots emerge.
A female Tuatara at the Auckland Zoo.
Being a vestige from the dinosaur age, tuataras are unlike any modern reptile. Tuataras sport a mouthful of saw-like blades. They have two rows of teeth on the upper jaw and one row on the lower jaw, an unusual arrangement for reptiles. But what distinguishes a tuatara’s teeth is that they are really just jagged extensions of the jaw bone, not actual separated teeth. Because of this, if a tuatara breaks or wears down a section of teeth, it has lost those teeth for the rest of its life because its teeth do not grow back like other reptiles.
New Zealand’s Other Living Relic
The size of a hamster, the giant weta is the world’s heaviest insect. The huge insect happily eats carrots and is too heavy to jump! Many people would find an insect this large repulsing and its name reflects that. It comes from the Maori word for “god of ugly things.” Like its predator, the tuatara, the giant weta is a living fossil, closely resembling relatives from 190 million years ago. Unfortunately the giant weta population has dropped drastically since the arrival of rodents slightly bigger than itself. Today, the giant weta has been completely wiped off mainland New Zealand and only survives on small offshore islands that are sheltered from rats. Thanks to a breeding program at the Auckland Zoo, the monster insect may be making a comeback.
Tuataras have incredibly slow metabolisms and are capable of surviving close to freezing temperatures and holding their breath for an hour. They hibernate during the winter and are capable of surviving months of refrigeration. Where the average reptile’s body temperature hovers around 68 degrees, tuataras have their internal thermometer set between 41 and 52 degrees. This decelerates their metabolism and also causes them to mature gradually, growing until they turn about 30 years old. While not quite having the longevity of a tortoise, tuataras can live to over a hundred years old, especially if their teeth hold up.
The strangest feature of a tuatara is that it possesses a third eye on the top of its head. Known as a parietal eye and complete with retina, lens, cornea and nerve endings, it is not used for sight. Some burrowing lizards and sharks also possess a parietal eye, which is capable of detecting light. Shortly after hatching, this primitive extra eye is covered with scales, but has stuck around because it has some function. It could possibly be used by the reptiles to absorb ultraviolet rays and set their circadian clocks.
New Zealand’s Lizards
Although tuatara are not lizards, New Zealand has more than 110 species of geckos and skinks, most of which are found nowhere else on earth. New Zealand’s geckos, in particular, are unusual because they give birth to live young. The only other place with geckos that do this is New Caledonia. Pictured here is an endangered rough gecko from the Auckland Zoo.
The tuatara quietly lived out its existence on the remote islands of New Zealand for millions of years. Adults are nocturnal, searching the damp forest floor for insects and young birds among the ferns, themselves relics from the Jurassic Period. Tuatara hatchlings are active during the day to avoid run-ins with potentially cannibalistic adults at night. Life, as they knew it in their undisturbed primeval forests, was good.
But then arrived humans, bringing rats with them. Tuataras, along with many of New Zealand’s endemic birds, were ill-equipped to deal with a predator unlike anything they had ever seen before. Rats gorged themselves on tuatara young as well as the eggs, ultimately eliminating the ancient reptile from all of mainland New Zealand. It seemed unlikely that a living relic that had persevered through a mass extinction caused by an asteroid 60 million years ago would quietly succumb to a hoard of rodents, but that is, in fact, what happened.
Between approximately 1800 and 2005, tuataras bided their time on small offshore islands that offered refuge from the invasive pests. Tuataras have been protected since 1895, but the first successful attempt to reintroduce them to the mainland was not until 2005 when a few were released in a sanctuary. In 2008, a tuatara nest was found, the first successful breeding attempt by a tuatara on mainland New Zealand in two centuries, offering a glimmer of hope that the strange scaly beast may survive yet again. Today there are around 55,000 tuatara dispersed on several islands between the North and South Islands.
Tuataras are undoubtedly a strange, alien creature from the distant past. Their perseverance has been incredible, outliving the rest of their kind in New Zealand’s ancient forests. Living fossils like tuataras are like time capsules: they have witnessed the disappearance of dinosaurs on New Zealand, scurried underfoot as towering moas travelled through the forest and barely survived the arrival of mammals. They act as a window into prehistoric times and will hopefully live on for millions of years to continue to tell the tale of New Zealand’s ancient past.
Windows to the past: peering into the eyes of an ancient relic is thankfully still possible today thanks to arduous conservation projects to protect the Tuatara and New Zealand’s other endemic species from rats and stoats. This picture was taken at the Auckland Zoo.
All photographs and art by Jack Tamisiea.
Sources:
https://www.wired.com/2013/12/the-creature-feature-10-fun-facts-about-the-tuatara-or-just-the-tuatara-of-us/
https://www.doc.govt.nz/nature/native-animals/reptiles-and-frogs/tuatara/
https://www.doc.govt.nz/nature/native-animals/reptiles-and-frogs/lizards/geckos/
http://mentalfloss.com/article/64804/10-intense-facts-about-giant-weta
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