Perfectly preserved prints from ancient flightless bird found in New Zealand
The moa went extinct between 700 and 800 years ago
Michael Johnston was out taking his boss's dog for a dip in a nearby river in Ranfurly, New Zealand, when he stumbled across some unusual markings embedded in the waterbed.
He had a hunch that he had found something quite special, and contacted the Otago Museum in the nearby city of Dunedin. There, researchers confirmed that the fossilized prints belonged to ancient flightless birds called moa, and were likely millions of years old.
"I was absolutely blown away by them when I first saw them," Kane Fleury, anatural science assistant curator at the Otago Museum, told As It Happens host Carol Off.
"The prints were amazing. They had crisp, square edges on them, and they were just very, very well-preserved."
They're the first moa prints found on New Zealand's south island. Fleury says they were preserved in sediment that could be anywhere from a million to 12 million years old.
Here’s a movie from <a href="https://twitter.com/KaneFleury?ref_src=twsrc%5Etfw">@KaneFleury</a> showing the Moa Footprint discovery site presently being excavated by the joint <a href="https://twitter.com/OtagoMuseum?ref_src=twsrc%5Etfw">@OtagoMuseum</a> <a href="https://twitter.com/otago?ref_src=twsrc%5Etfw">@otago</a> team <a href="https://twitter.com/hashtag/moa?src=hash&ref_src=twsrc%5Etfw">#moa</a> <a href="https://twitter.com/hashtag/museums?src=hash&ref_src=twsrc%5Etfw">#museums</a> <a href="https://twitter.com/hashtag/newzealand?src=hash&ref_src=twsrc%5Etfw">#newzealand</a> <a href="https://t.co/CqdwxTl6lQ">pic.twitter.com/CqdwxTl6lQ</a>—@iangriffin
"That potentially means that these are some of the oldest sort of evidence of moa in New Zealand," he said. "Because New Zealand such a geologically active country, it's not very well preserved."
Museum staff carefully extracted slabs of clay the weekend of May 11, after temporarily diverting much of the water away from the site and pumping the excess water, allowing them to cut the seven prints out. Each measured around 30 centimetres by 30 centimetres.
The prints were likely revealed after recent wet weather in the region, and could have been easily missed if flash floods buried them again under fresh mud.
"[There were] a number of logistical challenges to actually get to the prints because at this time of the year the river is starting to come up again and so, you know, they're under about a metre and a half, maybe a bit more, water," Fleury said.
"It's a lot of water to move."
Moa were large flightless birds endemic to New Zealand that went extinct around 700 to 800 years ago.
According to Fleury, they could range in size from about that of a large turkey to "giant" varieties over two metres tall and weighing as much as 250 kilograms.
He says the birds likely went extinct due to hunting within 100 years of human habitation in New Zealand.
"We know that they were quite a slow growing species that was slow to reach sexual maturity," he said. "So any high sort of hunting or predation pressures on a species like that can very quickly wipe them out, as we know from many other species around the world."
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Fleury says the bird or birds in question strode across the perfect mud to ensure their prints would be found so many years later.
"I would say that the mud was kind of, not super-wet and sloppy, but it was quite firm when it went in," he said.
"And it also wasn't kind of gloopy so that [their feet] pulled it up. So it was probably the perfect wet mud to walk through for preservation at the time," he said.
The mud likely dried out in the sun and was covered by sediment, he said, locking the prints in time until their recent discovery.
"It's kind of a freak chance of events to preserve a set of footprints like this," he said.
Here is a photo taken by <a href="https://twitter.com/iangriffin?ref_src=twsrc%5Etfw">@iangriffin</a> of Dan Parker helping to lift the final print from the Kyeburn. He manned a failing pump for two days straight. The seal finally failed as Marcus and I worked it loose. You can see the weight of the project lifting on our faces here. <a href="https://t.co/oL1wbPXz30">pic.twitter.com/oL1wbPXz30</a>—@KaneFleury
Otago Museum director Ian Griffin told the New Zealand Herald that the public may have to wait a few months before the prints are put on public display.
"There will be a lengthy process to safely dry them and ensure that both the footprints and the clay substrate remains stable," he said.
Fleury said it was "super cool" that Johnston contacted the museum so quickly after finding the prints.
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"[Johnston] was keen for us to go about protecting the prints because once he had found them, he was pretty worried about them," Fleury said.
"And he's a bit of a local joker, so he was a little bit concerned that we weren't going to take him seriously with his find, but we did take it very seriously."
Written by Jonathan Ore. Interview with Kane Fleury produced by Ashley Mak.