As It Happens

Scientists discover 1st evidence of 40-million-year-old Antarctic frog

A Swedish paleontologist looking through ancient sediment have made a surprising discovery — part of a 40-million-year-old hip bone which Thomas Mörs says is the first evidence of modern amphibians found in Antarctica

'I didn't expect to find a frog there,’ Swedish paleontologist Thomas Mörs says

An artist's rendition of the frog discovered by Thomas Thomas Mörs uses images by Simon Pierre Barrette and José Grau de Puerto Montt from Wikimedia Commons. (Illustration by Pollyanna von Knorring/Swedish Museum of Natural History/Scientific Reports)


Swedish paleontologists looking through ancient sediment have made a surprising discovery — part of a 40-million-year-old hip bone they believe is the first evidence of modern amphibians found in Antarctica 

Thomas Mörs, senior curator at the Swedish Museum of Natural History, and his colleagues released their findings in the journal Scientific Reports on Sunday. 

The small creature only measures around four to five centimetres in length, and is very similar in appearance to five living species of helmeted frogs that inhabit Patagonia. 

Mörs spoke to As It Happens host Carol Off about the discovery. Here is part of their conversation.

Can you take us to that moment when you are going through this sediment and you saw a little hip bone? What did you think? 

I work a lot with different kinds of smaller vertebrates. I'm quite familiar with different shapes, so I can see whether I have bones of a fish, amphibian, frog, salamander, snake, mammal or whatever. 

I saw directly that this was a frog. And of course, knowing that there is no frog known from the Antarctic, it was really, really exciting.

Mörs said he was 'very, very excited' after finding a bone fragment that later turned out to be the first evidence of an ancient frog living in Antarctica. (Jeremy Lee)

And a 40-million-year-old frog at that.

Well, being a paleontologist ... the age of 40 million years is not so stunning. I mean, there are some rocks that are double as old. But that [the frog] comes from the Antarctic is the important thing.

What else did you find other than this little creature?

There was a whole variety [of things], from small shark and ray teeth and scales, tons of bony fishes, small breeds of marsupial rats. We actually found cocoons of leeches and seeds of water lilies. 

There's a whole variety of both plant and animal remains that you find when you check it out under the microscope.

So you've found these kinds of fossils before, but this frog hip was something new?

Yeah, totally new. I mean, I didn't expect to find a frog there. 

A few days later, we found the skull. I knew that should also belong to a frog and probably to the same frog. Having the hip bone of a frog already meant it was quite probable that this bone would belong to the same [animal].

Unfortunately, both bones are rather fragmentary and I hope that I will get more complete material, nicer preserved.

What was the world like for this little creature 40 million years ago in Antarctica? 

The world was warm. There were giant snakes in the tropics. In the Canadian Arctic, there were crocodiles and primates roaming around. Generally speaking, it was a greenhouse climate at that time.

But at the Antarctic, glaciation had already started. We know this from drill cores and records around the continent. On the peninsula in West Antarctica, there were alpine glaciers developing high up in the mountains. 

An image showing part of the 40-million-year-old frog's hip. (Scientific Reports)

Do you know if this frog is an ancient relative of frogs on continents where they are now thriving? 

That was a surprising thing. Our frog actually represents a genus that nowadays lives in Chile, in southern rainforests, which are temperate and rather cool. 

There are not many species. Only five.

On the other hand, the species that are related to them have their roots not in South America with other frogs, but in frogs that live in Australia and New Guinea, which [were] part of an old super-continent, Gondwana, to which both South America and Antarctica belonged. 

Written by Adam Jacobson. Produced by Katie Geleff. Q&A has been edited for length and clarity.

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