Tuatara
Though it looks like a lizard, the tuatara of New Zealand is actually not closely related to lizards, and is the last surviving member of its own order – Rhynchocephalia.
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Rhyncocephalia
Family: Sphenodontidae
Genus: Sphenodon
Species: S. punctatus
Common Names: Tuatara (“Peaks on the Back” in Maori language, referring to the spines on the animal’s back)
Tuataras are nocturnal, meaning they are mostly active at night time. As they are cold-blooded animals, they frequently bask in the sun to absorb heat. They can tolerate temperatures below most other reptiles, and enter a hibernation state during winter.
Tuataras typically eat insects and other vertebrates including spiders, worms and snails. They also eat frogs, lizards, and bird eggs.
Tuataras do not reach breeding age until around 20 years old. Females will mate and lay eggs only once every four years. The reproduction rate is one of the slowest among all reptiles. Tuataras grow very slowly, and can live to be well over 100 years old.
Tuataras grow to two feet long, and are the largest reptiles in New Zealand. They are a greenish brown color, which can change as they grow older and can vary between individuals. A row of spines runs down their back, from their head to the end of their tail.
Tuataras have a unique feature called a parietal eye, which is a sort of third eye in their forehead. It has a lens, cornea-like structures, and a retina like a normal eye. However, it is completely coveredi n the adult tuatara, and only visible in juveniles. Its function is not known, but it may absorb ultraviolet rays.
Tuataras have very primitive hearing organs, and no external earhole is visible. Their teeth are unique, with two rows in the upper jaw and one row in the lower jaw, with the lower row fitting between the two upper rows when the mouth is closed.
The tuatara’s order Rhynchocephalia first appeared during the Triassic Period, the same era when the first dinosaurs appeared, around 250 million years ago. The current living tuatara has been around for about 20 million years, first appearing during the Miocene Epoch.
Tuatara were incorrectly classified as lizards by the British Museum in 1831, based on examination of a skull. It wasn’t until 1867 that they were recognized as their own distinct order, with similarities not only to lizards, but to birds, turtles and crocodiles as well.
Tuataras are a species of Least Concern. However, they still face threats, as they are only found in New Zealand. They have been protected legally in their home range since 1895. Like many other animals native to New Zealand, they are threatened by loss of habitat and predation by introduced, non-native species.
A group of Tuataras was discovered in 1989 on Brothers Island, a very small rocky island in New Zealand. Initially believed to be a second species, they are now thought to be a subspecies known as the Brothers Island tuatara.