- Paleontologists discover a fossilized frog dating to roughly 40 million years ago in Antarctica.
- The ancient frog’s anatomy bears a close resemblance to a living family of frogs called helmeted frogs (Calyptocephalellidae) which inhabit damp, temperate forests in Chile.
- The new research estimates Antarctica’s highest monthly average temperatures 40 million years ago would have been roughly 56 degrees Fahrenheit.
- The climatic timestamp could help scientists pin down how quickly Antarctica developed frozen sheets of ice amid the crackup of the supercontinent Gondwana.
The first fossil of a frog found in Antarctica gives new insight into the continent’s ancient climate, writes Alex Fox for Smithsonian Magazine.
Antarctica was not always a frozen rock at the bottom of the world. Earlier this month, analysis of a 100-foot-deep sediment core from the Antarctic ocean floor revealed the presence of ancient pollen, roots and other tell-tale signs of a rainforest that thrived there some 90 million years ago.
Now, paleontologists have uncovered an even more recent sign of the frigid continent’s balmy past: a fossilized frog dating to roughly 40 million years ago.
Antarctica: A once warmer place!
Forty million years ago, the Antarctic was home to a species of frog, adding to evidence that the now icy region was once much warmer and temperate.
The fossils of the first modern amphibian to be discovered in Antarctica were found on Seymour Island, part of the continent closest to the tip of South America.
The creature was tiny, around 4 cm to 5 cm long, but was very similar in appearance to the five living species of helmeted frogs that hop around Patagonia today, according to a new study published in the journal Scientific Reports.
“They looked like today’s frogs. No different. Our frog was rather small but this is in the range of the living ones, although most of the living ones are bigger,” said Thomas Mörs, a senior curator at the Swedish Museum of Natural History and an associate professor of paleontology.
He said the cold-blooded creature would likely have hibernated in mud during the region’s long, dark winters.
A rich and diverse place
Mörs explained that the frog would have lived in a temperate, humid rain forest very similar to those found in the Chilean Andes, where temperatures don’t vary much season to season.
It may have jumped on the pads of a now extinct water lily. Fossilized cocoons of leeches have also been found on Seymour Island, said Mörs, as well as a handful of mammals.
“My guess is that it [Antarctica] was a rich and diverse place. We have only found a percentage of what lived there,” he added. “The water lilies were the first hint that there were freshwater environment(s) there and it was not frozen all the time.”
The study’s findings suggested that the forests of South America may be a “modern analogue” of the Antarctic climate just before its glaciation and may now be home to other species originally found across the Antarctic Peninsula.
Intense and rapid climate changes
Earlier research has found that ice sheets formed across Antarctica before the final breakup of the southern supercontinent Gondwana into the present-day Southern Hemisphere, which includes South America and Antarctica.
Mörs said the climatic changes may have taken place very quickly, with nature making an intense retreat.
“This fauna lived 6 million years before the continent separated and then froze. There was glaciation likely already going on at the time,” he concluded.
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Source: Smithsonian Magazine
