Have you ever heard of a tuatara? Perhaps you just saw a picture of the adorable little creature and you want to learn more! Just looking at pictures or videos, you might think that a tuatara is a type of lizard, but you would be wrong–it is actually a member of a completely different class of reptiles. And this is only one interesting fact about the tuatara. So, what makes a tuatara unique? What does it have that no other animal on earth has? Keep reading! In this article, we’ll answer these questions and more.
What You'll Learn Today
What is a Tuatara?
A tuatara is a type of reptile only found in New Zealand. It is highly endangered; a federally-protected species since 1895, the tuatara was once thought to be extinct from mainland New Zealand before being brought from surrounding islands.
The tuatara looks somewhat like a small iguana; it can be anywhere between 12 and 30 inches long and is gray to greenish in color.
The name tuatara is a Maori word meaning “peaks on the back,” which is a good description of the creature–it has a row of white spines on its back. Both males and females have this row of spines, but it is more prominent in males.
Tuatara are land-dwelling reptiles who are most active at night. They spend their days basking in the sun to absorb its warmth, as, like other reptiles, tuatara are cold-blooded.
Tuatara don’t have ears, but their skeletal structure allows them to hear some sounds. They shed their skin; adults shed once a year, while juveniles may shed up to 3 or 4 times a year as they grow.
To learn more about the tuatara and get a great visual of this adorable lizard-like reptile, check out this video.
What is the Difference Between a Tuatara and a Lizard?
The tuatara looks like a lizard, but is not actually a lizard. It belongs to the order Rhynchocephalia, which is an ancient class of reptiles that has been around since before the dinosaurs.
The tuatara is the last living member of this order–others went extinct around 60 million years ago.
The tuatara has some similarities with the dinosaurs, but it existed long before they did and, obviously, has survived much longer.
Like lizards, tuatara can shed their tails when attacked and regrow them later. Though they share this characteristic with lizards, it doesn’t make them lizards–there are other reptiles who can do this as well.
How Similar is the Tuatara to the Crocodile?
The crocodile is a type of lizard, and, as noted above, the tuatara is a different class of animal altogether. Both crocodiles and tuatara are reptiles, but the similarity ends there–crocodiles and tuatara belong to completely different reptile families, much as rabbits and raccoons belong to different mammal families.
Crocodiles may be the oldest living creature on earth, dating back nearly 250 million years, but tuatara go back pretty far as well–about 190 million years.
Both crocodiles and tuatara are sometimes considered “living fossils” because they survived the rise and fall of the dinosaur age, and every age since then.
What Makes a Tuatara Unique?
- Only living member of Rhynchocephalia: As noted above, the tuatara is the last surviving member of its class, a class which dates back millions of years. There are only between 25,000 and 100,000 tuataras left in the world, and all of them are found on the islands of New Zealand.
- Longest gestation period in the animal kingdom: It takes female tuatara between two and four years to produce and lay a single batch of eggs. For this reason, they only mate once every two to five years.
- Live up to 120 years: The tuatara has an exceptionally long lifespan. It doesn’t reach sexual maturity until between 10 and 20 years of age, and it may continue living and reproducing for more than a century.
- Three rows of teeth: The tuatara has two rows of teeth on the top part of its jaw and a single row on the bottom; these rows of teeth fit together like scissors. The teeth are natural extensions of the jawbones, so once they are worn down and broken, they cannot be replaced.
- Surprising cold tolerance: Their body temperature fluctuates between 41 and 52 degrees Fahrenheit, which is much lower than most cold-blooded reptiles. As a result, their metabolism is slower and they are able to withstand colder ambient temperatures than most other reptiles.
What Does the Tuatara Have That No Other Animal Has?
A tuatara’s most unique feature of all is so different, so unique, that no other animal on earth has it. What is this feature?
A third eye.
That’s right, the tuatara has a third eye on the top of its head. This eye is functional and comes complete with lens, retina, cornea, optic nerves, etc, but it is not used for sight.
This third eye is only visible on very young tuatara, as it becomes covered with scales when the tuatara is only a few months old.
According to this article from Wired, scientists are not entirely sure of the eye’s purpose, but they hypothesize that it may be used to absorb UV radiation from the sun or to influence circadian rhythms.
The tuatara is also the only animal on earth with three rows of teeth arranged like scissors. No other animal has two rows of teeth on top with a third row on the bottom that fits between the top rows.
The tuatara is a unique lizard-like creature that appears to be left over from the dinosaur age. It has many unique features, including its status as the only remaining member of its class, its incredibly long lifespan, having the longest gestation period in the animal kingdom, the third eye on its head, and the three rows of teeth in its mouth.