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ScienceAugust 17, 2019

The giant parrot proves we have to save Foulden Maar


The recent discovery of a fossil parrot the size of a human toddler is even more reason for Foulden Maar to be protected, writes the chairperson of Save Foulden Maar, Kimberley Collins.

Last week, scientists discovered a new species of extinct parrot in the St Bathans Fauna. Weighing in at seven kilograms and standing just under a metre tall, it was around three times the size of a kākāpō, the world’s heaviest living parrot.

“Squawkzilla”, as it has been affectionately called by palaeontologists, was identified from a few leg bones found near St Bathans, an internationally significant fossil site in Central Otago. When they were found on a dig in 2008, it was assumed they belonged to an eagle already known from the area and the bones were “popped into a bag” for further analysis. Once in the lab, a PhD student named Ellen Mathers realised they weren’t eagle bones at all.

Heracles inexpectatus, aka “Squawkzilla”. Illustration by Brian Choo, Flinders University.

“I would say that terrestrial birds like Heracles are rare at this site” explains Trevor Worthy, an Associate Professor at Flinders University in Australia. 

Since scientists started excavating near St Bathans in 2001, they have recovered around 7,000 identifiable bones from up to 20 different sites. That’s not counting fish bones, of which they have hundreds of thousands. 

“Most [of the 7,000 bones] are birds that lived immediately in or around the lake. So they’re things like waterfowl, shorebirds and rails.” 

Worthy explains that the bones are in ancient lake deposits, having been transported and concentrated by water. 

“In some cases, there was a big flood and stuff got washed into the lake. Pebbles got washed down rivers. Dried clay on the shore was ripped up by the flooding and washed into the lake. These hard lumps of mud, called rip-up clasts, join the pebbles and bones to be rolled around on the floor of the lake. Often, they were covered in a patina [thin layer] of calcite, but after around a few months the layer of clasts, stones and bones was buried by mud and formed a conglomerate. So we target those places where a concentration mechanism is obvious — otherwise we’d be looking at blank walls of mud and it would be a very long process.”

Around 80 kilometres away, as the crow flies, is another incredible fossil deposit called Foulden Maar. Being a closed system with no streams or rivers to carry dead or dying animals, it has an exceptional quality of preservation by comparison with St Bathans. If Heracles inexpectatus had blundered its way into this crater lake, we may find a lot more than some leg bones.

Foulden Maar was formed 23 million years ago by a volcanic eruption. Magma rising through the Earth’s crust hit a body of water known as an aquifer to create a violent explosion of steam that sent the landscape sky-high. This left a small but very deep crater shaped like an ice-cream cone. As the dust settled, this filled with volcanic rock and schist debris, and then with water to create a steep-sided, flat-bottomed maar lake. 

Foulden Maar near Middlemarch in Central Otago. Photo by Kimberley Collins, Creative Commons CC-BY

“The sediment is mostly made up of diatoms, which are microscopic silica-bearing algae. Every spring and summer, these would have formed a bloom on the lake’s surface before dying off and sinking to the bottom to preserve whatever had fallen in that year” explains honorary associate professor Daphne Lee, who has been leading research at Foulden Maar.

Because of its depth, water at the bottom of the lake would have been anoxic, or devoid of oxygen, meaning whatever found itself on the lake bed was effectively pickled. 

“Anything that fell into the lake or was blown in has been pickled and then covered with that protective blanket of diatoms, and so on, for hundreds of thousands of years.” 

The most common fossils at Foulden Maar are leaves. Scientists have found tens of thousands of specimens. 

“Many of these have the entire cell structure of their cuticles preserved, which lets us see incredible detail. They are so thin and well-preserved that if it’s a windy day, the leaves actually peel off the rock and blow away.”

In the small deposit they have looked at so far, scientists have found hundreds of fossils, all of which are new species. They include orchid leaves, two of just five fossilised orchids in the world and flowers from 40 other different types of plant. They have excavated hundreds of insects, some with their eyes still intact, the Southern Hemisphere’s oldest freshwater eel, and even the earliest known member of the Galaxiiidae (whitebait) family.

“Some of the fish have actually got their gut contents preserved. You can see what it was eating before it finally drifted down to the bottom of the lake. So we now know that some of the galaxiids were eating insects and diatoms – there’s that level of preservation” says Lee.

This fossil of Galaxias effusus from Foulden Maar is is the earliest known member of the Galaxiiidae (whitebait) family. Photo by Stella McQueen, Creative Commons CC-BY.

If any bird had met its demise on the lake and sunk to the bottom, Lee says it would likely be a perfectly preserved skeleton, articulated with all its bones in place, and possibly even feather impressions or traces of actual feathers. 

“From what we know of other maars in other parts of the world that have been looked at really intensively, we will find whole animals that have fallen in and birds would be the likely one. We are really sure about that because we’ve got the Hindon Maar complex not too far away. It’s quite a lot younger but we have three bird feathers from there that are quite well preserved. We don’t know what they belong to yet but it means we would expect to find feathers attached to a bird in Foulden Maar which would be pretty amazing.”

Dr Mike Dickison, an expert on extinct giant flightless birds, agrees and adds that such a discovery would be of international significance and one of the most important fossil finds in avian evolution in the world. 

“A discovery like that would answer all our questions about the Heracles parrot that we just can’t answer from the St Bathans site. But it would also be one of the most beautifully preserved bird fossil specimens in the world. It would match some of the very best specimens from places like the Messel Shale in Germany where you can see the outline and feathers of birds.”

Foulden Maar and nearby Hindon Maar are examples of lagerstätte, fossil-rich deposits with exceptional preservation that can include the presence of soft tissues. 

“An example would be a site called Solnhofen in Germany which is where the first Archaeopteryx fossils came from. If those had been found somewhere else, no one would ever know that they were the first bird. But like Foulden Maar, the sediment at Solnhofen is so fine that the feather impressions were preserved on the skeleton so people could tell it was a bird and not just a little dinosaur” says Dickison.

Overseas, these lagerstätte are tourist attractions and an example of geo-tourism. The Messel Pit in Germany is perhaps the most famous of these, with a $6.5 million dollar visitor centre, daily tours, and at least three local museums showcasing its incredible fossil record. Meanwhile, just a stone’s throw from Foulden Maar, a Vanished World Centre and Geopark Trail in the Waitaki District has attracted tens of thousands of visitors since it opened in 2001, with numbers climbing steadily each year. 

“People travel from all over the world to see these places, do research, and publish on them. Foulden Maar is a similar sort of site and is at that same level of quality. Except almost nobody in New Zealand had even heard of it a few months ago.” 

Foulden Maar came to the public’s attention in late April, when a confidential report written by Goldman Sachs was leaked to the Otago Daily Times. This outlined plans by Plaman Resources, an off-shore mining company, to mine the maar in its entirety. The low-value diatomite would be exported and used as a scientifically dubious stock food supplement on factory farms and feedlots and as a fertiliser on environmentally destructive palm plantations in south-east Asia. This was followed by extensive media coverage, the creation of a Wikipedia page, support from former prime minister Helen Clark, a petition attracting nearly 11,000 signatures, a motion from Dunedin City Council in support of the maar’s protection and several public meetings. 

As the pressure mounted, Plaman Resources eventually buckled, going into receivership and liquidation in June. Last month, they withdrew their application with the Overseas Investment Office to purchase land that would allow their operation to be successful. 

However, the fight to save Foulden Maar is not over. Until the 42-hectares containing 80% of Foulden Maar is in public ownership, it is not safe from future mining. It’s critical that we ensure its protection for future generations, scientific research and the good of humanity. After all, who knows what we might find? 

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