Mangahouanga Stream is freezing, even on a sunny spring morning. Pete Shaw treads gingerly towards the water, wedging a walking stick between the river stones for balance. “F— that’s cold,” he yelps as he lunges in, floating towards the rocky shore.
Shaw is on a treasure hunt and, around here, if you want to find the good stuff, getting cold and wet is a given. The stream carves like a drainage channel through the upper Te Urewera ranges. Navigating it is an exercise in patience and pain tolerance. Steep banks rise on either side. When Shaw meets a stretch of water too wide to skirt and too deep to walk, he has no choice but to swim. With the initial shock and the swearing out of the way, he flips to his back and floats for a patch of scrabbly rock about 30 metres away. Almost immediately after wading ashore, he spots some loot.
“What’s that?” he says, scrambling around a boulder to get a closer look at a dark outcrop embedded in a rock. “I know what this is.” Vertebrae, he’s certain—and this one has a particular curve to it that he’s seen before. What we’re looking at, he’s pretty sure, is the remains of an enormous crocodile-esque marine lizard. It lived right here in the Cretaceous period, roughly 70 million years ago. “Mosasaur bone.” He describes the creature’s distinctive swishing swimming motion, the bladelike teeth that chomped sharks and other fish. “I could count on two hands the number of these I’ve found in 15 years.”
Shaw makes a mental note of where the fossil is located, but leaves it on the stream bank. There’s more to find. He picks up his stick, adjusts his wetsuit, and steels himself for another swim.
This stream is located in the depths of Maungataniwha, a 12,000-hectare block of forestry land and native bush at the northern tip of Hawke’s Bay. Shaw serves as a kind of caretaker for the area. He was appointed in 2005 by the block’s owner, Tasti snack foods magnate Simon Hall, to oversee a host of conservation initiatives, including replanting forestry land with natives and running a successful kiwi breeding programme. The land is remote—first, a winding 90-minute route from Napier towards Wairoa that’s prone to slips and closures; then another 45 bumpy minutes over gravel to get to Shaw’s main base of operations, Waiau Camp.
The area’s inaccessibility, along with its private ownership, means it’s comparatively unknown and seldom visited by the public. But Maungataniwha is one of our most significant geological sites. About 50 years ago, Joan Wiffen, a Napier farmer’s wife and budding fossil enthusiast, travelled there after finding a topographical map in the back of a toy store. The map had been put together by oil prospectors, and it had a note attached: Saurian bones in brackish water.
Wiffen and a team of fossickers packed up their canvas tents, drove north, and tramped through pine blocks to the southern end of Maungataniwha. There, they pushed through dense thickets of native trees until they found a way into that cold, brackish water. In the stream, they too found treasure. “Every one of the cold grey stones in the water seemed to sprout fossils,” Wiffen later recalled in her book Valley of the Dragons. “There were rocks encrusted with fish teeth, shark teeth, fish scales and vertebrae, gleaming on the surface.”
There were also those saurian bones the prospectors had seen decades earlier. Wiffen’s first major find was a theropod, or in Shaw’s words a “mini T-Rex”. It was the first true dinosaur bone ever found in New Zealand, and it changed how we understand our story.
Before Wiffen’s finds, it was believed the country had been separated from Gondwanaland for too long for it to have been home to dinosaurs. Afterwards, it became clear parts of the country had acted as life rafts, splitting off from the supercontinent in the late Cretaceous with giant lizards on board.
For the next 35 years, Wiffen and a team of fossickers made the long journey to the stream every weekend. Among much else, they uncovered the partial remains of an ankylosaur—the fossil of the tank-like plant-eater came to light in the wake of Cyclone Bola, in 1988. They found another plant-eater, one of the upright ornithopod family, and in 1999 Wiffen found a vertebra from the largest creature to walk the Earth, a titanosaur. (Think bulked-up diplodocus.)
Shaw is not naturally effusive, but back at Waiau he relays this information with something bordering on wonder. Wiffen is a hero to him. “She’s changed the way we see ourselves in the world. And we can’t redo that. And I don’t want to,” he says. “She really is a legend. But truly understated. Humble, but knowledgeable and capable.”
The pair met in 2008, a year before Wiffen’s death, at the “Rockhounds” hut her team built as a base above the Mangahouanga Stream. She was in her 80s, and her fossicking expeditions had slowed, but she was still travelling regularly to the area. Shaw wanted to know how to find a fossil. She explained he should look for concretions—harder rocks formed by sediment, and sometimes bits of bone, that build up over millions of years—and urged him to head to the meeting place of three tributaries known as the Triple Forks.
“So I went there thinking, ‘I won’t find a bloody thing,’” Shaw says. “And I looked down at my feet and right there was a bloody rock with bone in it. Right there. Exactly where she’d said to go.”
Shaw had caught the fossicking bug. For the next 15 years, he visited Mangahouanga in breaks from his pest-trapping and kiwi-conservation work, spending his off days trekking through frigid water, overturning rocks and peering under boulders. Waiau Camp is filled with his discoveries. Stones he’s hauled out of the stream are cluttered in doorways and scattered across shelves. During a dining-room conversation about the toothy 10-metre-long prehistoric marine reptile elasmosaurus, he remembers he has a visual aid. He nips out to retrieve it from near the front door, puts the rock on the dinner table, then rotates it to reveal the bone locked inside. “This is elasmosaur vertebrae,” he explains.
By late last year, many of the stream’s most interesting fossils had been harvested. The ones that hadn’t been extracted—because the rocks they were in were too heavy, or the fossils too similar to others found already—became dependable waypoints. When visitors showed up, Shaw would guide them to bones he’d uncovered previously. He’d show them the vertebrae of an elasmosaurus in situ, or tiny prehistoric fish bones hiding in pebbles. The stream still churned up new fossils every now and again, but it was mostly dependable, familiar. Until the night of 13 February, when all that Shaw once knew was erased.
When Cyclone Gabrielle hit Aotearoa’s East Coast, Shaw was sitting in a hut at Pohokura, a conservation block neighbouring Maungataniwha. Despite the sheeting rain, he wasn’t overly worried about his fossil-hunting grounds. A ridgeline shielded his hut from the worst of the cyclone, and it felt almost like any other bad storm. It wasn’t until he travelled to Maungataniwha later that week that he truly started to understand. Near the stream, the landscape had been completely reset. “It would have been a maelstrom. Just a heaving mass of rain and slips and things letting go,” Shaw says. “Hillsides sliding down, roads washing out, culverts blocking up and streams cutting through the roads. It was just madness.”
The storm churned up the soil of the native bush surrounding the stream, exposing bones once buried beneath the earth. It turned the once-chattering current into a seething rapid, scouring the streambed, overturning boulders and sending huge rocks tumbling hundreds of metres downstream. The water rose dramatically; some stone dislodged in the storm is still embedded in steep banks metres above the waterline. Other rocks that once sat high above the water have crashed to the shore.
When the flooding eased and Shaw made it back into the stream, what he felt first was profound disappointment. Familiar fossils had been buried under waves of silt or cut off by logjams. But as he kept rock-hopping, he found hope hidden within the wreckage. A host of other fossils, once inaccessible or out of sight, had been exposed. For the first time since Bola 35 years prior, the Mangahouanga had been completely reshaped. Shaw calls the stream’s new formation “a fossil supermarket”. It’s the closest he’s come to the experience Wiffen had when she first arrived and saw bones glistening on its surface.
“We’ve been smashed to bits,” he says. “The storm just wrecked us. We’ve still got roads that are knocked out. But the one upside is you go looking for fossils and it’s all new. Gabrielle puts us back to square one.”
The stream reveals new secrets on most of Shaw’s trips these days. Two of his most intriguing finds come from the same narrow, rocky patch of stream as where he found the mosasaur vertebrae, a short walk from the Rockhounds hut. The first is almost jarringly obvious. Less than a metre from the stream’s edge, a collection of clearly defined bones is wrapped like a garland around the top of a partially submerged rock. Shaw sends photos, or in some cases physical specimens, of all his more interesting finds to GNS Science/Te Pū Ao. Its paleontological team says these bones are from the late-Cretaceous carnivorous fish Pachyrhizodus caninus. It’s only the second fossil of this two-metre predator found in New Zealand. Wiffen found the first.
Another discovery may be even more significant. Before it was a boulder-lined stream, Mangahouanga was an estuary. Millions of years of uplift and erosion caused by tectonic movement drained much of the land and shunted the fossil-packed rocks to the surface. This aquatic origin story means dinosaurs, in the true scientific sense of the word, are hard to find here. The D-word is generally only applied to upright, land-based lizards—and for such a terrestrial creature to be preserved in the Mangahouanga’s rich seam of fossils, it would need to have either died in the lagoon or been washed there by rain. Another hurdle: vertebrae were far more likely to fossilise than other more fragile but scientifically informative bones. So it’s mostly vertebrae that Shaw finds, and most come from Cretaceous-period marine reptiles like mosasaurus or elasmosaurus.
But recently, a visitor found something that doesn’t seem to fit the mould. Te Papa exhibition developer Dan Parke came here to create video content for the museum’s ongoing Dinosaurs of Patagonia exhibit. Shaw gave his usual induction speech at the water’s edge, telling the museum staff to look for unusual concretions. Parke took it as a challenge. “I started looking, thinking, like, ‘Imagine if I found one.’” She brought rock after rock to Shaw, asking, “What’s this? What’s this?” She was getting her eye in.
When she spotted a split rock, with its flat side planted on the streambed, she thought it looked perfect. Hauling it up out of the water, she found a fossil fused into the rock. It was too heavy for her to drag to dry land. She asked Shaw for help. As they worked the rock free, “he was like, ‘Oh, my gosh’”. This fossil was different from the others in his collection. They hauled it out of the water and marked it off with pink tape. “The team was all teasing me that I found a cow bone,” Parke says. “Or saying, ‘Oh my god, this total amateur walks in and finds the next dinosaur fossil.’”
Well, maybe. Weeks later, Shaw returned to the rock and used a power saw to cut away the chunk containing Parke’s find. He carried it up the steep track in a backpack. Back in the living room at Waiau Camp that afternoon, he showed the specimen to Nadine Maue, a worker for the block’s kiwi breeding programme, and asked what bone the fossil resembled most. She gave it a quizzical look, then held her forearm parallel to the rock, as if to say “this one”.
The fossil is still being examined by GNS. Shaw is cautiously enthusiastic. “We’ve got no pirate treasure or anything like that,” he says. “We’ve got no stuff like they find in the UK where they go around with their metal detectors and find gold. In New Zealand, we’ve got archaeological sites. We’ve got things like moa bones, and we’ve got these fossils. They’re our treasure. Our taonga.”
If the rock does contain a dinosaur bone, it’ll be rare indeed: the first true dinosaur found in New Zealand since Wiffen’s discovery. (Right now, she’s still the only one to have a dinosaur find confirmed.) As with any treasure in New Zealand though, it’s unlikely that Wiffen, Shaw or Parke were really the first to dig these dinosaurs up. It was Māori that called the area Maungataniwha, or taniwha mountain. Toro Waaka, a kaumātua in the Hawke’s Bay iwi Ngāti Pāhauwera, says the name is an indication that Māori were the original fossil fossickers; the first to overturn rocks in the rapids and find evidence of huge creatures from the past.
This area, he says, was home to several Māori schools of learning, including one devoted to teaching women skills like crafting and how to use medicinal plants. It’s not easy terrain—but during times of famine “every inch of the country was necessary for survival”, he says. Foraging parties, looking for birds and plants, would have found the fossilised teeth and spines in the Mangahouanga and linked them to the legends they’d heard about taniwha.
Even though Ngāti Pāhauwera has strong links to Maungataniwha, Waaka is happy with the area’s current ownership. Simon Hall belongs to Ngāti Kahungunu and has tūpuna in the area. Waaka sees him, Shaw and their team as stewards to a long tradition of information sharing and environmentalism. When Māori found rocks encrusted with teeth and bone they saw deep time, and taniwha, and told stories accordingly. Shaw and his team are telling stories, too. They’re fleshing out the theories of the early Māori explorers with detailed, scientific information about the real monsters that once lived at Maungataniwha and the tectonic movements that brought their remains to us today. “There is a joining-up of dots to justify a lot of the kōrero that Maōri have,” Waaka says.
Shaw hopes he’ll be able to hold to Maungataniwha’s scientific tradition as he hunts down the fossils unearthed by Gabrielle. But he’s tired. At 64, he is fond of saying his body is a “bit buggered”. He pines for a younger person to take over exploring the Mangahouanga. That doesn’t mean he’ll stop though. For as long as he can, he’ll keep dragging a moderately buggered body into a frigid stream during his time off.
At the water’s edge, Shaw’s mate John Pascoe reflects on his friend’s tenacity. He says when Shaw used to work at DOC, he decided to use up two months of his annual leave searching for the “grey ghost”—the South Island kōkako, which hasn’t been seen in years and is now suspected to be extinct. He hired planes and travelled deep into the bush, mimicking the birds’ calls. It was fruitless. Shaw now thinks the kōkako are gone for good. But it’s telling that this extensive, exhausting hunt was his idea of a holiday. “If Pete was born two centuries ago, he’d be getting in a boat and going across the ocean to explore the hinterland,” Pascoe says. “All the hinterland has been explored now though, so I guess fossils are a way to get that sense of discovery.”
For Shaw it’s part of a personal evolution. He spent much of his life trapping possums and culling deer for pay. Back then, in the bush, his thoughts were usually consumed by how to eradicate pests more efficiently. Now he doesn’t take a gun when he guides hunters in this bush. He keeps tame deer at Waiau Camp, trudging out to feed them every night. He cultivates rare plants he finds in the hills, and stops regularly during walks to deliver lessons on the local flora.
As his body packs in, his capacity for wonder is expanding. He still carries out pest control, regularly ordering 1080 drops in the back blocks of Maungataniwha, but his focus has shifted from the uglier parts of nature to its beauty. “I wish I’d known what I know now about our country back then. I wish I’d known it—oh, shivers—45 years ago. Because I walked through our back-country landscape, mainly in Te Urewera, and I just didn’t understand it at all. I thought I did. But all I was looking for was critters to kill,” he says. “I just came to realise there are rare species here I knew nothing about. There’s human history here I knew nothing about. And there’s fossil history in here I knew nothing about. And all of it was fascinating.”
The fossils aren’t just history though. They’re a portal. The creatures now encased in rock at Maungataniwha lived in a place that would have been unrecognisable to us. There were no Southern Alps. No volcanoes. The forest’s upper storey was dominated by different species of conifer. Everywhere—on land, in the sky and in the sea—reptiles both massive and tiny were trying to kill each other. “You turn over a rock and there’s this link to that other world,” says Shaw. “It’s a way to travel in time.”