Creature Out of Time: The Last in its Line

Writen By Nathan Kettler

Photos by Nathan Kettler

Cold Roaring-Forties raced over the Hauraki Gulf and their sunset-painted waves battered the greywacke shores of Tiritiri Matangi Island (aptly te reo Māori for “tossed by the wind”) where they replenished old tide pools and stronger waves pushed further still and violently deposited troves of Neptune’s necklace and salt-spray to Hobbs Beach, where I happened to be visiting that evening with old coworkers; Katie and Issac, a couple I met just last year during my touring days at Yellowstone National Park and now here they were, engaged to one another since I last saw them and they’d come all the way to New Zealand, in part to spend time with me. What a treat to see old friends in a new land I had just moved to for my schooling but a month ago.

South Island takahē (Porphyrio hochstetteri), one of the most iconic dinosaurs of Tiritriti Matangi Island, Hauraki Gulf, New Zealand. (Photo by Nathan Kettler)

Katie, Isaac, and I first bonded as tour guides in Yellowstone over our shared hobby of observing living dinosaurs in their natural habitats. Heck, I’ve seen four-hundred-thirty-one species of dinosaur in my twenty-five years alive. Of course, none of us have seen any Tyrannosaurus or Brontosaurus; all my sightings belong to the only living group of dinosaurs left being those warm-blooded, feathered reptiles: the birds. That’s my extremely overdramatic but scientifically correct way of saying we’re, of course, birdwatchers. We saw about thirty new birds in the last forty-two hours, many of which are endangered and thrive on invasive-mammal-free Tiritiri. Highlights included seeing our lifer South Island takahē, North Island kōkako, and red-crowned parakeet all in one morning. So, despite popular misconception, the dinosaurs in their eleven thousand avian forms are alive and well overall.

That night, however, we were on the hunt for a very different kind of ancient reptile. We pushed along the wrack, rocks, and sand of the beach. Across the gulf to our left was Auckland on the distant shore,e and the skyline illuminated the fading horizon, commanded by a needle-like concrete sentinel, the Sky Tower. To our right, salty gales swayed old Pōhutukawa and cabbage trees in Tiritiri’s hills and the unfamiliar stars of this foreign hemisphere began their shift in the night sky as we followed a northbound trail into the forest and gained elevation in the beach’s cliff-faces where the southwestern winds eased their blow on us behind protective thickets of Mānuka. Here, in the secluded bush trails, we suddenly made out a more organic rustling among the foliage to our left.

“Could it be?” I thought to myself with anticipation.

We drew our flashlights on the clamor, but whatever it was had gone.

“Do you think it could have been one of those lizards?” Katie asked, and since it was the fifth time I’d reminded her, all I could say was a deadpan, “If you call them lizards one more time, I swear”.

“Dinosaurs! Sorry!”

“GRRR! They’re not dinosaurs, either!”

“Reptiles!”

“…good enough.”

I smiled; I always love good banter with friends.

Moments later, another unseen rustling was heard from our left again, then another from the right. It seemed that every few steps, something large and low-slung was scurrying in every direction away from us and narrowly evaded our sights in the underbrush whenever we swiveled our headlamps towards it.

Then, a few more yards and at around the sixth attempt, I heard Isaac whisper: “Nate, look.”

Tuatara (Sphenodon punctatus) on Tiritriti Matangi Island, Hauraki Gulf, New Zealand. (Photo by Nathan Kettler)

And I eagerly followed his beams towards my first sight of a living, breathing two-hundred-forty-million-year-old fossil. It lay silently on a bed of leaf-litter, in all two feet long with spines, some upright and others lopsided, running up the ridgeline of its scaly, splotchy green-brown body from its tail to its big, box-ish head which carefully judged us three mammals with the leftmost of its three ancient eyes. My jaw was on the floor, it was a tuatara.

The tuatara superficially resembles a lizard; it might be mistaken for an iguana from the Americas, but a lizard it is not. It’s the last member of its proud lineage, a dynasty that hit its stride in the Jurassic period, and today, only one species remains, found in New Zealand and nowhere else. It is a rhynchocephalian, a lineage of reptiles closely related to but distinct from the lizards, who have only been on Earth for a casual one-hundred-seventy million years

Diversity in Rhynchocephalia over millions of years, interrelationships of the order’s extinct genera are shown as well as the order’s relationship to Squamata (lizards, inc. snakes). (Illustration provided by Current Biology)

As I mentioned in passing, yes, the tuatara does in fact have three eyes. It has two opaque, glassy, refractive corneas, one on each side of its head, for focusing on images, and a third primitive eye on the roof of its skull for sensing changes in sunlight, used for moderating its nocturnal lifestyle. As interesting as this is, it shares this seemingly alien trait with many other reptiles, along with amphibians and various fishes. What distinguishes tuatara from most other reptiles is in the cut of their teeth. Their fore-teeth make an incisor-like “beak,” and their hind-teeth are fused together to their mandibles, creating a single enamel plate in the bottom jaw that neatly slides through two plates on the upper jaw. This makes their dentition perfect for shearing through the chitinous exoskeletons of insects such as giant wētā, the shells of petrel eggs, and even the tough hides of hatchling tuatara. Tuatara have low metabolisms even for reptiles, with much less efficient circulatory systems than lizards as tuatara haphazardly mix oxygenated and deoxygenated blood in their primitive little hearts. They live long lives, over one hundred years, and eat very infrequently. This metabolism also means, of course, that they are quite lethargic by nature and can’t run far or exert themselves for long. The rhynchocephalia held on to their very existence for eighty million years in the isolated, mostly submerged stronghold of Zealandia while lizards with oxygen-discerning hearts pumped rich blood through their bigger, meaner, faster bodies and, over millions of years, displaced the primordial relics on all other continents.

The distinctive skull and dentition of a tuatara (Photo by Piotir Naskrecki, 2017).

I gawked with child-like awe and shot a photo of the beautiful little cannibal before it exploded with movement a short distance into the thicket where it rested again. Here on this island sanctuary, the tuatara could rest at its leisure without fear of rats, possums, or stoats, which had long eliminated it from mainland New Zealand since the arrival of the Pākea (Europeans) in the eighteenth century

Five more tuatara crossed our path as we kept strolling through the bush, and I was delighted and enraptured. Everything about this night, this place, and this animal was precious. How fortunate was I? To be here in New Zealand with friends from the world’s first National Park, admiring this creature out of time, the last in its line.