Craig Mckenzie

Tomb with a view

Until recently, scientists didn’t think our amber held any insects. Now, they’ve found more than 200 specimens—immaculately preserved, and each telling a story about our prehistoric past.

Written by       Photographed by Craig Mckenzie

The digger tears at the grazing country of west Otago, peeling back the grass and topsoil, the fungi, nematodes and worms, gouging down to sand and mud—the vomitings of a river that once meandered across this land. It takes only a few minutes to chew through millions of years of geology. The digger breaks through into a shockingly dark layer.

Before the engine is even turned off the geologists are leaning in, peering from the hole’s rim at the land’s long-buried innards. As soon as it’s safe, there’s a scramble.

Palaeontologist Uwe Kaulfuss, leading this expedition, is a kid in a lolly shop. “I’ve been fossil hunting for so many years, but it’s still exciting,” he says as he clambers down.

I join them, rummaging in the greasy, chalky mess, crumbling it apart in my hands, trying to read the material like these people can.

The layers the digger stripped back tell a story stretching tens of millions of years into the past. This field has seen the sea rise and fall, seen it push inland bringing seashells and sand, then retreat, giving way to the forest. The dark stuff we’re touching now is that forest transfigured: it’s called lignite.

Lignite is the poor cousin of the coal family. West Otago and neighbouring Southland sit on great wedges of it—about six billion tonnes buried beneath kale crops, sheep paddocks and dairy sheds.

Kaulfuss and farmer Andrew Morris fossick through lignite—low-grade coal—on Morris’s property in Tapanui, west Otago. This site produces huge amounts of fossil-containing amber.

Unlike higher grades of coal, lignite is not fully petrified. It still vaguely looks like a forest. The team has found preserved tree trunks in this spot, standing upright as they did in life. We uncover slabs of blackened wood big enough to eat a picnic off. Strips of bark flake apart as if peeled from a tree yesterday. The whole black mess smells woody and earthy, wet and old. To a fossil hunter, it is a treasure trove.

The forest we’re knee-deep in was dominated by trees in the family Araucariaceae—it’s a particularly resinous group of trees, one that includes kauri. These trees might have even been kauri. It’s just one of the questions we can’t answer for sure—yet. Palaeontology is forever a game of glimpses and best guesses, and finding new ways to see.

And precious clues to our prehistoric past are scattered throughout this lignite. Chunks of amber, mixed in like hokey pokey: some the size of a brick, others as small as coins. The pieces with insects inside look just like all the others—for now.

To a palaeontologist, finding these tiny insects is just as exciting as digging up a buried bone. “Each one tells the same story as a mammal or a crocodile,” says Kaulfuss.

[Chapter Break]

As of 15 years ago, we’d found only six insect fossils in the whole of New Zealand. They were tiny fragments preserved mostly in mudstone—a wing here, part of a carapace there. Pieces too few and too broken to even identify a species. The entire evolutionary history of insects in this country was an enormous blank.

That’s because insects are terrible at turning into fossils. They have no hard bits like bones or teeth; their soft body parts quickly disintegrate and biodegrade.

But there is one way that insects can be preserved, and in astonishingly fine detail.

Picture the scene here 25 million years ago: a forest of towering kauri, branches alive with birdsong. This was a warmer time—let’s say crocodiles lurk at the fringes of the swamplands. And of course, everything hums with insect life.

A spider spins its web on the side of a great tree. Meanwhile, sticky, golden resin drools from a tiny chink in the tree’s bark.

The spider makes a misstep and finds its leg stuck to the resin. It struggles for a while, until its energy is gone, and dies as another flow of resin slowly encases it in a golden tomb.

The resin dries and hardens and breaks off the side of the tree to land among the roots. Over time, the resin, or “gum”, as it is known in the kauri forests of Northland, is buried, along with the remains of the tree that formed it. Time strips it of all its volatile elements—it becomes fossilised. At this stage, it is called amber. It keeps its treasures for eternity.

New Zealand amber is filled with tiny air bubbles which can make it hard to see inclusions such as this 23-million-year-old spider.

In amber from other parts of the world, scientists have found extraordinary moments of ancient life frozen in time—a spider in the process of attacking a fly, a scale insect with 60 eggs on her back, termites mating. They have even found lizards and dinosaur feathers encased in amber.

Despite the amazing true stories amber can hold, it was a fiction—the 1993 film Jurassic Park, in which dinosaurs are resurrected using DNA from the gut of a preserved mosquito—that saw demand for the substance soar.

The most famous amber-producing area in the world is the Baltic region. Its remarkably clear, golden amber has been traded for millennia, and mined for hundreds of years. Beloved of fossil collectors and often used as jewellery, this amber is now selling, mostly in China, for up to NZ$7500 a kilogram. If a piece contains a fossilised insect, it might bag six figures.

Ninety per cent of the world’s amber comes from just a tiny corner of this region: Russia’s Kaliningrad Oblast, where amber supports more than 20,000 people. The amber is gorgeous but the industry is riddled with corruption, violence and smuggling. It has also caused untold environmental destruction. A similarly nefarious industry has recently emerged in Ukraine. There, an unprecedented “amber rush” has seen thousands of hectares of forest reduced to muddy wasteland.

Morris first found amber when he was digging a drain on his farm. He took chunks home in his pocket, well before scientists revealed the secrets it was keeping.

Perhaps fortuitously, New Zealand amber is not so lovely. Instead of being alluringly translucent it is brittle, opaque, and filled with tiny air bubbles that make identifying anything in it virtually impossible to the naked eye. For decades, it was assumed that our amber did not contain  “inclusions”, as trapped insects and other curiosities are known. Not that many people were looking. For the most part, it was only curious coal geologists who took a passing interest.

Palaeontologist Daphne Lee used to take chunks of amber home every time she went to a coal mine on a field trip. She’d sometimes clean it up and arrange it on a shelf in her office at the University of Otago.

“We kept it because it was pretty. We looked at it with a hand lens, but we could never see anything in it.”

In 2010, at a conference in Budapest, she went to a talk given by German amber scientist Alexander Schmidt.

Schmidt’s talk was about using chemicals to dissolve certain kinds of tropical amber in order to release its inclusions. Perhaps, Lee wondered, we could do the same thing with New Zealand amber? When the presentation finished, she approached Schmidt.

Lee told him we had lots of amber in New Zealand, but that it didn’t seem to have anything stuck inside. “He said, ‘I’m sure it does.’”

The scientist suggested Lee send over some samples. When she got home, she packed up a few pieces and couriered them off.

“I didn’t have great expectations,” she says.

Almost every fossil insect found in New Zealand has come either from amber, or from one of two famous sites in Central Otago—the extinct volcanic crater lakes of Foulden Maar and Hindon Maar (pictured). These maars are packed with plant, insect, bird and fish fossils. Kaulfuss is a regular visitor here, searching for insects to complement his amber finds.

New Zealand amber resists easy inspection—unlike some kinds, it cannot be dissolved. But Schmidt was able to fill the air bubbles, clarifying the amber so he could peer in. Then he emailed Lee the first-ever images of a New Zealand insect contained in amber—a 0.25 millimeter-long mite. At a glance Lee could see scimitar-like claws, reproductive organs, and gut contents.

“I was just totally overwhelmed,” she says. She printed the pictures off and toured the geology department, waving them in front of everybody.

“This is a whole new world that we knew nothing about.”

A major field of study had just opened up. Lee secured an $810,000 Marsden grant to study the secrets of our amber.

[Chapter Break]

Andrew Morris, the digger driver, farms dairy cows out here in the backblocks of west Otago, and knew about this amber years before the geologists became interested in it. “I was just out here digging one day, putting in a drain, and I ran into this seam of the coal,” he says.

“I pulled this stuff out and I was pretty sure it was gum.”

Morris threw a few chunks of the amber in the pocket of his work pants, to be deposited in a cardboard box on the mantelpiece at home later. There the bits stayed for several years—a curiosity to show visitors—until one day a young geology student called Henry Gard came wandering up the Pomahaka River in search of fossilised shell beds, which he was mapping for his thesis.

Morris handed Gard the chunks of amber and he took them back to the University of Otago geology department, where they were brought to the attention of Lee and also Kaulfuss, at the time a PhD student, who was working on the amber project with her. They drove out to the farm for a closer look.

Compared to the clear, golden amber found overseas, New Zealand amber resists scrutiny—the hunt for insects inside is a long grind. “I can’t wait to get back to the department to put it under a microscope and see how well it’s preserved, and what it really is,” Kaulfuss says.

Then, as now, Morris obliged with the digger—he recalls that when he first clawed open the lignite layer, he barely had time to stop digging before an astonished Kaulfuss fell upon the black deposit like a seagull following a plough.

What Kaulfuss discovered in that pit was one of the most important amber sites yet found in New Zealand. That was a decade ago and the team has only just scratched the surface of the stories this place can tell. “It’s going to be years before the whole picture is built up,” says Lee, “but we’ve actually got a whole ecosystem preserved.”

I join Kaulfuss as he rifles through the lignite. He’s based back in Germany now, at the University of Göttingen, but is in New Zealand for a few weeks of fossicking. His excitement has not faded.

“I never get bored and never get tired of fossil hunting,” he tells me.

“For me, it’s just the most amazing thing. My strategy is to expect nothing so I’m never disappointed at the end of the day.”

When he does find something, though, the excruciatingly long hours spent dredging through mud and clay, often in awful weather, are worth it. “It doesn’t matter what kind of fossil it is, my hands are shaking.”

Unlike some traditional fossil hunting, where leaves and insects pop out at the splitting of chunks of mudstone, amber hunting in New Zealand is a slow burn.

“In the field you can’t really know if there’s something in it,” says Kaulfuss. “It’s opaque, so if there’s a spider or something sitting right in the middle, you won’t see it.”

Kaulfuss is especially looking for stalactite-shaped pieces of amber—the sorts of long stems formed when resin oozes slowly over a period of time, building up layer upon layer. Each layer is another chance to trap insects.

Hundreds of chunks of amber might not reveal a single fossil. But, Kaulfuss says, “it only takes one piece that’s made up of many different layers, then you can find dozens and dozens of insects”.

Finding amber in a place like this is not hard—it’s mixed all through the lignite—but searching for insects inside it is incredibly time-consuming. Kaulfuss takes the most promising bits back to Germany, where he and a small team of students painstakingly scrutinise them under a microscope. “Sometimes we’re finding nothing for a month. Sometimes it’s finding 10 insects a day.”

When most of us think of insects in amber, these are the kind of images that spring to mind—delicate critters perfectly visible in a clear golden substance, as famously depicted in the film Jurassic Park. New Zealand amber is usually murky and full of air bubbles, so such immaculate examples are hard-won, and take many days of meticulous preparation work.

Every insect found is a cause for celebration in the laboratory. “If it’s from a site where we haven’t had anything before, that’s actually the most exciting thing. Because then we know we have a new amber locality.”

Typically, insects stuck in amber do not show any signs of a struggle. They are suspended in an apparently calm and relaxed state, as if they had accepted their sticky fate before entering their sleep-of-a-million-years.

Once the team finds an insect, says Kaulfuss, “that’s where the work really starts”. First, they delicately grind and sand the amber back, coming to within a fraction of a millimetre of the edge of the  insect.

The now-tiny chunk of brittle amber then needs to be itself smothered in epoxy resin to stop it falling to pieces. Before the epoxy hardens, the whole thing is put in a vacuum, drawing epoxy into the air bubbles and cracks, which makes the insect inside more visible.

Some samples—the ones where a shadow of an insect can be seen, but not identified, or where whatever’s inside is heavily obscured by air bubbles—are taken to a behemoth of a machine to be scanned. The DESY synchrotron in Hamburg has a two kilometre-long particle accelerator and is one of the world’s most in-demand scientific instruments. In order to use it, Kaulfuss and his team have to apply for a time slot months in advance. When they’re called up, the waiting is not done—they have to check into a hotel in the city and be on call 24/7 until it’s their turn. It might be 3 in the morning.

What comes back are thousands of images—thin “slices”—that can be put together to make a three-dimensional computer model of the insect. The preparation of these models takes a lot of time, so Kaulfuss has to choose wisely the samples he sends to scan. The results, though, are breathtaking.

“In the end, you get a model which you can move in any direction you want to. You can zoom in and zoom out so you can basically see every detail that’s preserved in the insect.

“It’s almost like looking at a living insect that you collected in the field, except that it’s millions of years old.”

Pictured are some of the best specimens Kaulfuss and his team have achieved so far. On this page, an as-yet unidentified insect from Andrew Morris’s farm at Pomahaka. This larva with air bubbles clinging to its bristles, was also found at the Morris farm. “Although the general preservation is exquisite,” says Kaulfuss, “a foam of small bubbles around the body obscures details.” The bubbles probably formed as the larva, unprotected by the exoskeleton of adult insects, started to decompose.
Trees exude resin to seal up wounds and defend themselves against insect damage. Kaulfuss looks for stalactite-shaped pieces, which are created by recurring amber flows, as these often contain dozens of trapped insects.

After the epoxy and the vacuum and the sanding, after the scanning, there starts a long process of describing the insect that has been revealed. Kaulfuss is not an entomologist—he relies on dozens of experts from around the world to figure out which species, genus or family each insect belongs in. It’s a lot of back and forth and admin, a slow grind. For all intents and purposes Kaulfuss is the only scientist working on New Zealand’s fossil insects and, I realise, he is faced with an impossible task—to find, identify and scientifically describe New Zealand’s entire known fossil insect fauna. “It won’t be finished in my lifetime,” he says.

Very little is known about how insects evolved in the southern hemisphere. But now, because of Kaulfuss’s work, and Lee’s, the palaeontological record of ancient New Zealand insects has jumped from six to over 750—and counting.

They have found pseudoscorpions. Parasitoid wasps. A mite that looks at first glance like a plastic bag or a jellyfish, suspended in tea. They’ve found fungus gnats, feather mites, a single lonely ant, springtails, leaf beetles, fairy flies, carpet beetles, scale insects. Four midges, entombed together. A booklouse that died millions of years before books arrived. Various spiders, the best of them replete with filaments of web, preserved fecal pellets and insects caught by the spider before the spider was caught by
the resin.

Other ecological interactions are snapshotted too. Most notably, a parasitic mite clinging to the back of a midge, and a fungus in the process of devouring a nematode worm. To Kaulfuss, these finds are the most exciting.

And the level of detail is amazing—the scientists have photographed the hairs on beetle larvae, the scattered, loose wing scales of a moth or perhaps a butterfly. They have spotted fungal spores in the guts of mites, counted the segments in a wasp’s “foot” (or tarsomere), and examined the bristles that fringe its wing.

The 40 million-year-old parasitoid wasp pictured here is tiny—less than one millimetre long.
This marsh beetle was found in Hakataramea, south Canterbury.

There is one question I am culturally obliged to ask. I can see by his wry grin that Kaulfuss knows it’s coming before it’s even out of my mouth. Even the most respected of palaeontologists has watched Jurassic Park.

“Absolutely not,” says Kaulfuss. “They are too old. The insects are still there, they look like insects, but it’s all chemically modified, there is no DNA left.” So no bringing an extinct spider back to life then? Perhaps we could resurrect some ancient New Zealand crocodiles and open up a Steve Irwin-style “Miocene Park” as a new tourist attraction for Gore?

Yeah, nah.  “I’m not sure that would be a good idea in any case,” says Kaulfuss.

So far, we’ve found amber at more than 40 sites around the country. At seven of those we’ve found amber with insects inside it.

New Zealand, it is now understood, has an amber record stretching back almost continuously 70 million years—from the age of the dinosaurs right up to modern kauri gum. It’s thought to be the longest continuous amber record of anywhere in the world.

[Chapter Break]

In a few years’ time, when—funding permitting—hundreds more insect species will have been described from New Zealand amber, scientists will be able to get a much clearer picture of how insect groups have come and gone from our little breakaway chunk of Gondwana.

Studying these insects is important for understanding our ancient ecosystems, Lee says,  “because they’re most of it”.

Thomas Buckley, an entomologist with Manaaki Whenua – Landcare Research, studies the living insects of New Zealand, about which, by his measure, we still know very little. Insects, he says, are crucial to study because they play so many different roles in an ecosystem. “They’re predators, they are involved in nutrient recycling, they are herbivores. They occupy every kind of ecological niche you could possibly imagine. So, if you really want to understand ancient environments, it’s really critical that you know what’s going on with insect diversity.”

Most of what we can surmise about ancient insects in New Zealand comes from DNA analysis done on living insects—tracing quirks and changes in genes through time. Fossil insects provide concrete evidence.

By lining up the two sets of clues, says Buckley, we can start to work out which groups of insects have thrived here under different climate regimes and which have gone extinct.

“If we can know what kind of turnover and extinction we get in species when the climate changes, or when pests arrive, that can help us predict what might happen in the future.”

Before the revelation that our amber contained insects, Daphne Lee was consumed by her work at Foulden Maar, a rare crater lake that records, in epic detail, tens of thousands of years of deposits from the Miocene epoch. This column of sediment hidden beneath a paddock contains a multitude of fossilised leaves, flowers, insects, fish and fungi. Lee was using the fossils to reconstruct the ancient ecosystems that lived around the lake.

Identifying insects in amber is just one piece of the puzzle. To understand the ecosystem they lived in, it’s also crucial to identify the plants they lived amongst.
For that, Kaulfuss relies on Dunedin paleobotanist Jennifer Bannister, who prepared and identified this fossilised leaf, an ancient relative of kāmahi, from Foulden Maar. The small holes in this leaf are made by insects eating it.

Buckley tells me that while this maar and another nearby, Hindon, still offer extraordinary, focused snapshots of ecosystems at specific places and times, the amber record, which is found all around New Zealand and covers a far longer time period, is “potentially going to give us a much more widespread view”.

Kaulfuss says that while it’s early days, the outline of that view is emerging. “Some of the insects we’re finding are very closely related to things that are still around in New Zealand,” he says. “We also find insects that are now extinct.

“What we are really interested in seeing is patterns. What’s become extinct and why, and what’s still around. What group was more diverse than it is now?

“Each little find, each little insect or spider, is just another piece of the jigsaw puzzle.”

The very fact that this hunt never ends is what keeps Kaulfuss going. “There will never be a point where we can say we know everything that lived here,” he says. “We’ll always be finding new things.”

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